Can somebody help me figure thisout? The Electronic Gallery is a retail storespe
ID: 2915783 • Letter: C
Question
Can somebody help me figure thisout?The Electronic Gallery is a retail storespecializing in video games. Prospective employees are separatedinto groups of 12 and are given a test of reasoning ability. Basedon past results, 70% of the prospective employees pass the test.Find.....
a) the mean number of prospective employees per group who pass thetest.
b) the standard deviation for the number of prospective employeesper group who pass the test.
c) the probability of having exactly 8 prospective employees passin a given group.
d) the probability of having at least 8 prospective employees passin a given group.
Please if someone can help me with this problem show all work.Thank you will give a Lifesaver.
Explanation / Answer
This is a binomial distribution with p = .7. This implies anumber of things... a) mean = sample size * passing rate = 12 * .7 = 8.4 b) stdev = sqrt(n * p * (1-p) ) = sqrt(12 * .7 * .3) = 1.587 c) A pdf of P(X=x) = C(n, x) * p^x * (1-p)^(n-x): P(X=8) = C(12, 8)* .7^8 * .3 ^4 = .231 d) At least 8 implies P(x=8) + P(x=9) + p(x=10) + P(x=11) +P(x=12). I'll let you calculate it.