OLD Barrows Drop Rate, Finally Resolved!

[primadog]

Requesting more barrow logs /w kc!

 

 

 

 

 

 

 

Premise: Barrows drop is not rare, nor is it affected by kc, time spent, or style, with evidence.

 

 

 

 

 

 

 

Summary

 

 

 

6 brothers = 6 drops, the chest holds all the drops.

 

 

 

each drop has 1/60 chance to be barrows item.

 

 

 

If not barrows/d med/half key, the drop can be the following:

 

 

 

|~300 mind | ~150 chaos | ~75 death | ~50 blood | ~35 bolt | ~500 gp

 

 

 

6-7 KC | 1 | 1 | 1 | 0 | 0 | 4

 

 

 

8 KC | 1 | 1 | 1 | 1 | 0 | 3

 

 

 

9+ KC | 1 | 1 | 1 | 1 | 1 | 2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Myth: Barrow drops are rare. FALSE

 

 

 

Evidence: the average rate for barrows items is 1 per 10 trips, or 1/60 for each barrows brother. This is assuming you kill all six brothers.

 

 

 

ref:

 

 

 

(only counting barrows drops as for now)

 

 

 

my own data 12 out of 122 trips 9.7%

 

 

 

19-20-574-40948124 4 out of 45 trips 8.9%

 

 

 

19-20-272-39981415 13 out of 162 trips 8.0%

 

 

 

19-20-685-40892430 8 out of 72 trips 11.1%

 

 

 

19-20-605-34726195 35 out of 360 trips 9.7%

 

 

 

19-20-626-25865127 14 out of 140 trips 10%

 

 

 

19-20-516-35296675 25 out of 382 trips 6.5%

 

 

 

mc90123's log 9 out of 204 trips 4.4%

 

 

 

---------------------------------------------

 

 

 

total: 120 out of 1487 : 8.07% (requesting more barrow log counts)

 

 

 

 

 

 

 

acceptable range: 120 +/- 24 (at 95%)

 

 

 

expected at 1/60: 148.7 items

 

 

 

Acceptable as for now? YES! but barely

 

 

 

 

 

 

 

Myth: Drop rate depends on kc(kill count)/method/time taken. FALSE

 

 

 

Evidence: look at the above examples, the drop rate is incredibily steady, regardless of personal style.

 

 

 

 

 

 

 

Myth: You can't figure out the chances. FALSE

 

 

 

Chances:

 

 

 

Each brother you kill give you one drop (clones don't count). You get maximum of 6 separate drops from the six brothers you kill. If the drop isn't a barrows or half key or d med, then it is dropped by the following ratio:

 

 

 

 

 

 

 

|~300 mind | ~150 chaos | ~75 death | ~50 blood | ~35 bolt | ~500 gp

 

 

 

6-7 KC | 1 | 1 | 1 | 0 | 0 | 4

 

 

 

8 KC | 1 | 1 | 1 | 1 | 0 | 3

 

 

 

9+ KC | 1 | 1 | 1 | 1 | 1 | 2

 

 

 

 

 

 

 

ie, if you have 8KC, you have 1/7 chance to get ~300 minds, ~150 chaos, ~75 deaths, ~50 bloods, and 3/7 chance to get ~500 gold for each brother you killed, assuming you didn't get a barrows drop.

 

 

 

 

 

 

 

Evidence:

 

 

 

1) Look at my drop log, Looking at the default values and compare to each drop, you will notice that every single one of them can be counted as six different drops by the six different brothers.

 

 

 

 

 

 

 

Example:

 

 

 

Trip 57

 

 

 

Loot- 299 mind, 37 bolt, 1010 gp, 128 chaos, 70 death

 

 

 

 

 

 

 

From this data and looking at the average drop table, we can conclude that the brothers had 1 mind rune drop, 1 bolt racks drop, 2 gp drop, 1 chaos rune drop, and 1 death rune drop ( 1+1+2+1+1 = 6 brothers! ).

 

 

 

 

 

 

 

2) Looking at the drop summary from my blog:

 

 

 

From only 72 trips ( or 72 * 6 = 432 drops), look at how close that resembles the drop rates I posted above.

 

 

 

14007 Mind rune / ~300 = 46.69 / 432 drops = 10.8%

 

 

 

7629 Chaos rune / ~150 = 50.86 / 432 drops = 11.7%

 

 

 

4217 Death rune / ~75 = 56.23 / 432 drops = 13.0 %

 

 

 

2399 Blood rune / ~50 = 47.98 / 432 drops = 11.1 %

 

 

 

2672 Bolt racks / ~35 = 76.34 / 432 drops = 17.7 %

 

 

 

71256 Gp / ~500 = 142.51 / 432 drops = 33.0 %

 

 

 

7 barrows = 7 / 432 drops = 1.6%

 

 

 

1 half key = 1

 

 

 

 

 

 

 

 

 

 

 

3) Add up the drop counts from above:

 

 

 

46.69+50.86+56.23+47.98+76.34+142.51+7+1=428.61

 

 

 

ie 428 drops

 

 

 

This is data from 72 trials, so I killed

 

 

 

72 * 6 = 432 drops

 

 

 

 

 

 

 

429 v. 432, pretty close for something random, isn't it?

 

 

 

 

 

 

 

4) Summary of data from other players, summarized by KC alone:

 

 

 

 

 

 

 

The data is rather quite large and complicated. The basic idea is in random variables the average value approaches expected value, so if we have average a large number of chest drops based on KC, we can expect the average chest drop to be similar in ratio to that we expect (as above).

 

 

 

 

 

 

 

The summary of chest drop by KC using beechworth, mattb3, and my data: http://www.nd.edu/~xhong/runescape/OutputSum.htm . The more runs we have at a particular kc, the closer is it to the ratio we expect.

 

 

 

 

 

 

 

If we group the KC by 6-7, 8, or 9+, the relationship is ever clearer:

 

 

 

 

 

 

 

 

 

 

The ratios are very clear now.

 

 

 

 

 

 

 

 

 

 

 

BOTTOM LINE: WHAT THE CHEST HOLDS IS NOT AFFECTED BY KC**, TIME SPENT, METHOD!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

*In case you're wondering why the sum is not 100%, here's the details:

 

 

 

 

 

 

 

There's a 1/10 chance that you can get a chance to get a rare drop. This is called a 'rare drop wheel' or a second 'wheel'

 

 

 

 

 

 

 

(my current data is that detailed enough for me to decipher the drop rate of this second wheel. Thus, all of below are SPECULATION! If you can link me to more data, it will be very helpful)

 

 

 

 

 

 

 

1/10 rare drop wheel as follow:

 

 

 

any of the 24 barrow pieces ~1/200?

 

 

 

d med ~1/200?

 

 

 

half key ~7/200?

 

 

 

-------------------------

 

 

 

1/200 * 24 + 1 / 200 + 7 / 200 = 33 / 200 = 1 / 6

 

 

 

Thus, a rare drop has a 1/6 * 1/ 10 = 1/ 60 chance

 

 

 

 

 

 

 

The rest of the rare drop wheel is equivalent to the normal drop ratio:

 

 

 

300 MIND 1 : 150 CHAOS 1 : 75 DEATH 1 : 50 BLOOD 1 : 35 BOLTS 1 : 500 GP 1

 

 

 

 

 

 

 

**One interesting calculation we can do:

 

 

 

 

 

 

 

we can find the average worth of a chest at 6-7 KC, 8, or 9+.

 

 

 

 

 

 

 

mind runes - 20 gp

 

 

 

chaos runes - 135 gp

 

 

 

death runes - 300 gp

 

 

 

blood runes - 550 gp

 

 

 

bolt racks - 330 gp

 

 

 

 

 

 

 

6-7 KC: 1/7 * 300 * 20 + 1/7 * 150 * 135 + 1/7 * 75 * 300 + 4/7 * 500

 

 

 

8 KC: 1/7 * 300 * 20 + 1/7 * 150 * 135 + 1/7 * 75 * 300 + 1/7 * 50 * 550 + 3/7 * 500

 

 

 

9+ KC: 1/7 * 300 * 20 + 1/7 * 150 * 135 + 1/7 * 75 * 300 + 1/7 * 50 * 550 + 1/7 * 35 * 330 + 2/7 * 500

 

 

 

 

 

 

 

6-7 KC: 7250 * 6 = 43500

 

 

 

8 KC: 11107 * 6 = 66642

 

 

 

9+ KC: 12686 * 6 = 76116

[primadog]

converted the three main data files i used into spreadsheet in case someone else want to give the data a try:

 

 

 

 

 

 

 

http://www.nd.edu/~xhong/runescape/beechworth.xls

 

 

 

http://www.nd.edu/~xhong/runescape/mattyb3.xls

 

 

 

http://www.nd.edu/~xhong/runescape/newbiei.xls

 

 

 

 

 

 

 

 

 

 

 

LOG as evidence:

 

 

 

others used for summary purposes:

 

 

 

19-20-574-40948124 4 out of 45 trips

 

 

 

19-20-272-39981415 13 out of 162 trips

 

 

 

19-20-685-40892430 8 out of 72 trips

 

 

 

19-20-605-34726195 35 out of 360 trips

 

 

 

19-20-626-25865127 14 out of 140 trips

 

 

 

 

 

 

 

Newbiei

 

 

 

Detail: http://www.nd.edu/~xhong/runescape/blog/newbiei.txt

 

 

 

This is newbiei's barrow log, ouput on Thu Mar 29 04:38:33 2007

 

 

 

Total Trips: 112

 

 

 

Total Worth: 14135072 gp || Average per trip: 126206 gp || Average per hour: 575064 gp

 

 

 

Total Time Spent: 24.58 hours || Average per trip: 13.17 min

 

 

 

~~~~

 

 

 

=============Summary=============

 

 

 

27851 Mind rune

 

 

 

13615 Chaos rune

 

 

 

6298 Death rune

 

 

 

2988 Blood rune

 

 

 

2779 Bolt racks

 

 

 

127756 Gp

 

 

 

2 Guthans helm

 

 

 

1 Dharoks platelegs

 

 

 

1 Torags helm

 

 

 

1 Torags hammers

 

 

 

1 Ahrims robetop

 

 

 

2 Ahrims staff

 

 

 

2 Karils crossbow

 

 

 

1 Karils leathertop

 

 

 

1 Karils coif

 

 

 

14135072 value

 

 

 

1 Half key

 

 

 

112 run

 

 

 

~~~~

 

 

 

 

 

 

 

beechworth's blog, origin: 19,20,516,35296675

 

 

 

Detail: http://www.nd.edu/~xhong/runescape/BLog/beechworth.txt

 

 

 

This is beechworth's barrow log, ouput on Mon Mar 26 13:10:59 2007

 

 

 

Total Trips: 379

 

 

 

Total Worth: 46845999 gp || Average per trip: 123604 gp || Average per hour: 292787494 gp

 

 

 

~~~~

 

 

 

=============Summary=============

 

 

 

46845999 value

 

 

 

379 run

 

 

 

1 Guthans platebody

 

 

 

3 Veracs helm

 

 

 

2 Veracs brassard

 

 

 

1 Veracs flail

 

 

 

1 Veracs plateskirt

 

 

 

1 Dharoks greataxe

 

 

 

2 Dharoks platebody

 

 

 

1 Dharoks helm

 

 

 

1 Dharoks platelegs

 

 

 

3 Torags hammers

 

 

 

1 Ahrims robeskirt

 

 

 

1 Karils crossbow

 

 

 

1 Karils leatherskirt

 

 

 

3 Karils coif

 

 

 

2 Dragon med helm

 

 

 

15 Half key

 

 

 

94917 Mind rune

 

 

 

40933 Chaos rune

 

 

 

27811 Death rune

 

 

 

13645 Blood rune

 

 

 

12076 Bolt racks

 

 

 

356250 Gp

 

 

 

~~~~

 

 

 

 

 

 

 

mc90123's barrow log, based on his post on the second page

 

 

 

Detail: http://www.nd.edu/~xhong/runescape/BLog/mc90123.txt

 

 

 

This is mc90123's barrow log, ouput on Mon Mar 26 14:17:22 2007

 

 

 

Total Trips: 204

 

 

 

Total Worth: 29739797 gp || Average per trip: 145783 gp || Average per hour: 1486989850 gp

 

 

 

~~~~

 

 

 

=============Summary=============

 

 

 

29739797 value

 

 

 

204 run

 

 

 

1 Guthans warspear

 

 

 

2 Guthans helm

 

 

 

2 Veracs flail

 

 

 

1 Torags platebody

 

 

 

1 Torags helm

 

 

 

1 Ahrims robeskirt

 

 

 

1 Ahrims hood

 

 

 

4 Dragon med helm

 

 

 

11 Half key

 

 

 

51937 Mind rune

 

 

 

22406 Chaos rune

 

 

 

12574 Death rune

 

 

 

7192 Blood rune

 

 

 

6851 Bolt racks

 

 

 

202617 Gp

 

 

 

~~~~

 

 

 

 

 

 

 

mattyb3's blog from post

 

 

 

http://www.nd.edu/~xhong/runescape/BLog/mattyb3.txt

 

 

 

This is mattyb3's barrow log, ouput on Tue Mar 27 11:06:15 2007

 

 

 

Total Trips: 73

 

 

 

Total Worth: 6196807 gp || Average per trip: 84888 gp || Average per hour: 619680700 gp

 

 

 

Total Time Spent: 0.01 hours || Average per trip: 0 min

 

 

 

~~~~

 

 

 

=============Summary=============

 

 

 

6196807 value

 

 

 

73 run

 

 

 

1 Ahrims robeskirt

 

 

 

2 Ahrims hood

 

 

 

18934 Mind rune

 

 

 

10302 Chaos rune

 

 

 

5772 Death rune

 

 

 

1473 Blood rune

 

 

 

966 Bolt racks

 

 

 

91827 Gp

 

 

 

~~~~

[jemathonical]

Nice :)

 

 

 

 

 

 

 

I love that blog too, lots of effort

[dude_of_war4]

what jema said

[meb]

Almost 300 chests, not even close to 30 items. I don't thnk it's very accurate.

[pulli23]

50 runs...

 

 

 

 

 

 

 

only 1 half key (didn't know that counted as "speciality").

 

 

 

 

 

 

 

 

 

 

 

But I think this can be an avarage (a friend of mine had from the 20 barrow runs 5 items...)

[primadog]

You're not guaranteed to get 30 item out of 300 chests, probability don't work that way.

 

 

 

 

 

 

 

However, if you get less than 19 items or more than 41, it's evidence that my conclusion is wrong. If so, let me know.

 

 

 

 

 

 

 

reason:

 

 

 

In binomial distribution:

 

 

 

average drop = number of runs * brothers killed * chance

 

 

 

deviation = ( number of runs * brothers killed * chance * ( 1- chance ) ) ^ .5

 

 

 

 

 

 

 

There's a 5% chance that your drop count is larger than average drop +/- 2 * deviation

 

 

 

 

 

 

 

Based on yours:

 

 

 

 

 

 

 

average drop = 30

 

 

 

deviation = 5.4

 

 

 

 

 

 

 

there's a 95% chance that your drop count will be within 19 to 41 items.

[n64jive]

hmm, I'd have to say your luck was just very good.

 

 

 

 

 

 

 

1 in 10 is deffinately not an average considering people go 20-50-80-100 trips without drops all the time...

 

 

 

 

 

 

 

I have friends who have never had a drop from barrows and do it regularly.

[Ryuuka]

very nice :thumbsup:

 

 

 

 

 

 

 

only 1 thing, you can get lucky(so it is always when you got a "chance" fr something) my friend got real lucky and got 2 guthan spears in 8 RUNS!!!

[Sjakie_1_1_3]

Your pretty lucky. I've done 100 runs and only had 1 half key :wall:

[DjKarate]

hmm, I'd have to say your luck was just very good.

 

 

 

 

 

 

 

1 in 10 is deffinately not an average considering people go 20-50-80-100 trips without drops all the time...

 

 

 

 

 

 

 

I have friends who have never had a drop from barrows and do it regularly.

 

 

 

 

 

 

 

lets say each run is not determined by the outcome of the last so therefore you can go 100s of runs without a drop since 90% of the time (according to the data) you wont get a drop...just create a random number generator from 1-10 or 1-10000 or something and see how many times you get numbers below 10% (which would indicate how often you get a barrows drop according to this data)...then take into consideration if each run is based off the previous, do other people's outcome determine yours? there are many outlying factors that can explain why people go 100s of runs without a drop...nice data though...too bad moridin isnt around...he did a huge data compilation with bell-shaped curves and statistical analysis to prove something (cant remember, friend irl showed me it around 4 years ago)

[wretched_axe]

hmm, I'd have to say your luck was just very good.

 

 

 

 

 

 

 

1 in 10 is deffinately not an average considering people go 20-50-80-100 trips without drops all the time...

 

 

 

 

 

 

 

I have friends who have never had a drop from barrows and do it regularly.

 

 

 

 

 

 

 

If you have 1 out of 10 change it doesn't mean that after 9 times no drop you'll get one the 10th. For example, tossing a coin has 1/2th change of landing on head right? If you toss a coin 20 times I almost want to bet it doesn't come out on 10 head 10 tails :-w ( my math teacher actually did this in class, very funny convo's :lol: )

[chenw]

That doesnt explain why you cant get anything BUT chaos, deaths, minds and items if you kill ONLY the brothers. You CANNOT get bloods or boltracks without killing at least something else.

 

 

 

 

 

 

 

Go do 100 runs with 6kc, you WILL find that KC has an effect on the chest (and ONLY 6kc)

[Risen_The]

Great thread mate, I agree with it almost completely. :) I still think there's "luck" down there somehow....

 

 

 

 

 

 

 

*friend does 70 trips, 2 items*

 

 

 

 

 

 

 

*I do 30 trips, 1 item*

[primadog]

That doesnt explain why you cant get anything BUT chaos, deaths, minds and items if you kill ONLY the brothers. You CANNOT get bloods or boltracks without killing at least something else.

 

 

 

 

 

 

 

Go do 100 runs with 6kc, you WILL find that KC has an effect on the chest (and ONLY 6kc)

 

 

 

 

 

 

 

working on that right now. I'll report when i have a good size count.

 

 

 

 

 

 

 

EDIT1: i been doing 6 kc for the past ten runs, it appears that indeed you don't get blood & bolts at that, i'll have to modify the hypothesis about this, but i'll need further data.

[DjKarate]

 

 

 

Go do 100 runs with 6kc, you WILL find that KC has an effect on the chest (and ONLY 6kc)

 

 

 

 

 

 

 

when i barrowed, thats all i did was get 6kc and ive only had 2 drops in probably the 35-40 runs ive done (2 guthan helms) and i never got bolt racks, half keys or whatnot...usually runes and cash which is fine by me tbh...but if what other people get determines what youll get then yes, KC does not matter...we could also look at it from a more complex standpoint and state that each outlying variable plays a part in what you get (damage taken from each monster, time spent getting to chest, time taken to kill each barrow brother, number of monsters encountered while running, pathway taken, number of doors entered and number of doors to find 6th brother, weapon/armor/food of choice...etc...) but i dont think jagex incorporated all of that...we shall await the data though

[DarkDude]

The way I believe it works is that the drops are NOT worked out until you get to the chest.

 

 

 

 

 

 

 

Each Brother "drops" an item, however this is not worked out until the other kills are taken into consideration. Maybe it's something to do with the last x monsters you killed which effects the odds.

 

 

 

 

 

 

 

Eitherway, kill count does effect it, maybe it just adds possible rewards?

[Uula]

72 runs is far from good evidence, you would need like 5000 of them for at least some accuracy. Anyway, I think Leesters said something about certain drops ages ago, which has pretty much been proved correct. So... I'll disagree. I don't do any barrowing anyway, but I do disagree with a 72 chest log.

[deucedeuce22]

The way I believe it works is that the drops are NOT worked out until you get to the chest.

 

 

 

 

 

 

 

Each Brother "drops" an item, however this is not worked out until the other kills are taken into consideration. Maybe it's something to do with the last x monsters you killed which effects the odds.

 

 

 

 

 

 

 

Eitherway, kill count does effect it, maybe it just adds possible rewards?

 

 

 

 

 

 

 

 

 

 

 

I think this was proven ages ago, the drops arent determined until you open chest. I can recall several trips were I would open the chest and server would crash, and Id open it again with different results. It also means that each brother can drop any of the 24 possible items, the drops arent keyed to who you kill or when, its keyed to the chest and what you kill.

 

 

 

 

 

 

 

Technically you could crash the server into giving you that Guth spear everytime. Open the chest, get whatever barrows item or items, then crash the server if you didnt get the ones you wanted. Come back, its like a chest reroll.

 

 

 

 

 

 

 

 

 

 

 

To the first post---none of that data is a real surprise, its pretty much been known after the first barrage of tests ages ago. Leesters had similar odds on everything, just 1/12 for a barrows item. Not sure why people are still bothering with it...

[arkwelded]

i think it all comes down to some kind of factor built in to characters. let me explain.

 

 

 

 

 

 

 

i have an insane drop rate for rare items from slayer creatures. about 1:300 for the rare specialty item(whip, black masks, mystic items, metal boots, ect)

 

 

 

my dragon drop rate is very high too, that may be due to the amount of boss creatures i kill. even creatures like fire giants, metal drags, ect are very good to me. i have gotten 4 chains, 9 meds, 3 spears, 2 sheilds, 2 2-hnders, 3 legs, 4 skirts, i lost count of axes after 40 :P .

 

 

 

on the other hand my barrow drop rate stinks. i have well over 1000 chests and only 4 barrows drops(all junk), and 2 d meds. while the runes pay for the trip, the items are not there.

 

 

 

 

 

 

 

i have freinds with many drops from barrows and nowhere near the drag and slayer drops i have. the controls are not in place for a totally acurate comparison, but IMO something is programed into each account. it may be a way to balance the game items.

 

 

 

 

 

 

 

just my thoughts and experiances

[das]

Interesting data..

[noble_skull]

You're not guaranteed to get 30 item out of 300 chests, probability don't work that way.

 

 

 

 

 

 

 

However, if you get less than 19 items or more than 41, it's evidence that my conclusion is wrong. If so, let me know.

 

 

 

 

 

 

 

reason:

 

 

 

In binomial distribution:

 

 

 

average drop = number of runs * brothers killed * chance

 

 

 

deviation = ( number of runs * brothers killed * chance * ( 1- chance ) ) ^ .5

 

 

 

 

 

 

 

There's a 5% chance that your drop count is larger than average drop +/- 2 * deviation

 

 

 

 

 

 

 

Based on yours:

 

 

 

 

 

 

 

average drop = 30

 

 

 

deviation = 5.4

 

 

 

 

 

 

 

there's a 95% chance that your drop count will be within 19 to 41 items.

 

 

 

That's normal distribution tbh, not binomial.

 

 

 

 

 

 

 

and deviation = sqrt(#runs*chance*(1-chance))=sqrt(300*.1*.9)=sqrt(27)

 

 

 

 

 

 

 

Standardising gives: X-u=Z*o = X-30=invNorm(.95)*sqrt(27)

 

 

 

 

 

 

 

So there's a 95% chance that the drop count will be within 22 and 38 if im not mistaken. Then again, I might be wrong.

 

 

 

 

 

 

 

Apart of that, it's a nice theory.

[primadog]

http://www.stat.yale.edu/Courses/1997-98/101/binom.htm

 

 

 

 

 

 

Mean and Variance of the Binomial Distribution

 

 

 

The binomial distribution for a random variable X with parameters n and p represents the sum of n independent variables Z which may assume the values 0 or 1. If the probability that each Z variable assumes the value 1 is equal to p, then the mean of each variable is equal to 1*p + 0*(1-p) = p, and the variance is equal to p(1-p). By the addition properties for independent random variables, the mean and variance of the binomial distribution are equal to the sum of the means and variances of the n independent Z variables, so

 

 

 

 

 

 

 

 

 

 

 

 

 

I am currently in desperate need of more barrow logs to research though, if anyone can contribute links, it'll be greatly appreciated.

[noble_skull]

http://www.stat.yale.edu/Courses/1997-98/101/binom.htm

 

 

 

 

 

 

Mean and Variance of the Binomial Distribution

 

 

 

The binomial distribution for a random variable X with parameters n and p represents the sum of n independent variables Z which may assume the values 0 or 1. If the probability that each Z variable assumes the value 1 is equal to p, then the mean of each variable is equal to 1*p + 0*(1-p) = p, and the variance is equal to p(1-p). By the addition properties for independent random variables, the mean and variance of the binomial distribution are equal to the sum of the means and variances of the n independent Z variables, so

 

 

 

 

 

 

 

 

 

 

 

 

 

I am currently in desperate need of more barrow logs to research though, if anyone can contribute links, it'll be greatly appreciated.

 

 

 

Hmm normal and binomial distribution must have different meanings in English then.

[Wachtwoord]

 

http://www.stat.yale.edu/Courses/1997-98/101/binom.htm

 

 

 

 

 

 

Mean and Variance of the Binomial Distribution

 

 

 

The binomial distribution for a random variable X with parameters n and p represents the sum of n independent variables Z which may assume the values 0 or 1. If the probability that each Z variable assumes the value 1 is equal to p, then the mean of each variable is equal to 1*p + 0*(1-p) = p, and the variance is equal to p(1-p). By the addition properties for independent random variables, the mean and variance of the binomial distribution are equal to the sum of the means and variances of the n independent Z variables, so

 

 

 

 

 

 

 

 

 

 

 

 

 

I am currently in desperate need of more barrow logs to research though, if anyone can contribute links, it'll be greatly appreciated.

 

 

 

Hmm normal and binomial distribution must have different meanings in English then.

 

 

 

That's probably true, Dutch is one of the very few languages which got his own words for math terms.