>hypothesis test: return befor and after the same,个人认为是卡方分布。
F-test (chi-square: variance = 0, f-test var1 / var2 = 1)
>compare to continouse uniform distribution,the probability of discrete uniform distribution? A lower B higher c the same 选了C,因离散分布各个取值的概率相同,不知对否。
In a given range, continuous: P(X=c) = 0; discrete: P(X=c) > 0
> 9.cash paid to supplier A.29000 B.32000 C.35000 选了A
COGS: $32000, increase in inventory: $3000, inc a/c payables: $3000
-> $32000 + $3000 (unsold inventory) - $3000 = $32000