6 Statiscal Distribution

Question 1

Random variable

Answer 1

A variable whose value depends on the outcome of a random event

Question 2

Sample space

Answer 2

The range of values that a random variable can take

Question 3

What is the mass probability function?

Answer 3

A way of showing the probability of each outcome
Eg for a dice being rolled
P(X=x)=1/6 x = 1, 2, 3, 4, 5, 6

Question 4

When can you use binomial distribution?

Answer 4

When
•there are a fixed number of trials
•there are two possible outcomes (success and failure)
•there is a fixed probability of success
•the trials are independent of each other

Question 5

What is the formula for binomial distribution?

Answer 5

Bin(n,p)

n)p^r(1-p)^(n-r
(r)

Question 6

10 fair coins are tossed, find the probability of 6 heads

Answer 6

H~bin(10,1/2)

P(H=6) = (10)(1/2)^6(1/2)^4
6

Question 7

What is a cumulative probability function?

Answer 7

Tells you the sum of all the individual probabilities up to and including the given value of x in the calculation P(X<=x)