Binomial Distributions Mean and Standard Deviation
p ,16,18 p ,22,24
Make a probability Distribution for X~B(5,.25). This is called a Binomial PDF x P(x)
µ x = σ x =
Form the Binomial CDF. x P(x)
Suppose James guesses on each question of a 10 item multiple choice test with four choices for each question. p(X > = 1) P(x > 6)
The Practice of Statistics, Third edition - Content The Practice of Statistics, Third edition - Content
If x~B(n, p) then P(x≤ k) = binomialcdf( n,p) Is approximately ~N(np, sqr(npq)) so P(x ≤ k) ~ normalcdf(lower,k, np, sqr(npq))
One way of checking for Undercoverage, Nonresponse, and other sources of error in a sample survey is to compare the sample with known facts about the population. About 12% of American adults are black. The number X of blacks in a random sample of 1500 adults should therefore be X~B(1500,.12)
What is the mean and standard deviation of X? Find p( 165≤ x≤ 195) using the binomial formula and by using the Normal approximation to the binomial