Question

hello, please write down each step on how you got the answers. thank you for your help.

1. A survey of City Tech students found that 35% say they get their lunch from the salad bar in the cafeteria. A random sample of 140 students is selected and asked if they get their lunch from the salad bar in the cafeteria.

1. What is the probability that at most 55 say “Yes”?
2. What is the probability that more than 40 say they get their lunch from the salad bar in the cafeteria?
3. What is the probability that between 50 and 60, inclusive, say they get their lunch from the salad bar in the cafeteria?

Answer 1

Let X denote the number of people who get their lunch from the salad bar in the cafeteria. Then

Using Normal approximation to Binomial distribution,

a)

Required probability =

b)

Required probability =

c)

Required probability =