Question

26. During a typical day, 58% of people in the US with Internet access go online to get the news. In a random sample of 80 people, use an Excel function to find the binomial probability that the number of people that go online to get the news is
    1. 44 or less
    2. exactly 45
    3. more than 50

Then, Find the mean and standard deviation of the binomial distribution. Show the use of the special formulas.

Answer 1

a,b and c are calculated using excel and refer the following

n	80
P(Internet access)	0.58
P(No Internet access)	0.42
X=No of people having Internet access
P(X<=44)	0.33179067
P(X=45)	0.085244838
P(X>50)	0.176758837

Excel Has a function	binom.Dist
Arguments
Number_s	Number of successful trials	44	45	50
trials	Number of trials	80
Probability of success	P(S)	0.58

mean of binomial distribution

Standard deviation =