According to a study, the probability that a randomly selected teenager shopped

Question

According to a study, the probability that a randomly selected teenager shopped at a mall at least once during a week was 0.65. Let X be the number of students in a randomly selected group of 50 that will shop at a mall during the next week. (a) Compute the expected value and standard deviation of X. expected value standard deviation (b) Fill in the missing quantity. (Round your answer to the nearest whole number.) There is an approximately 2.5% chance that or more teenagers in the group will shop at the mall during the next week.

Explanation / Answer

p = 0.65
n = 50
q = 0.35

(A)
expected value = np = 32.5
std. dev. = sqrt(npq) = 3.3727

(B)
For 0.025, z-value = 1.96
xbar = mean + z*std.dev
xbar = 32.5 + 1.96 * 3.3727
xbar = 39.1105

There is an approximately 2.5% chance that 39 or more teenagers in the group will shop at the mall during the next week

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.