Question

Foot Locker uses sales per square foot as a measure of store productivity. Last year, the mean annual sales per square foot was $370 with a standard deviation of $38.54. Suppose you take a random sample of 64 Foot Locker stores operating last year. There is a 86% probability that the sample mean annual sales per square foot is at least $______. a. None of the answers is correct b. 375.2029 c. 364.7971 d. 328.3768 e. 411.6232

Answer 1

Solution:

Given that,

mean = = 370

standard deviation = = 38.54

Using standard normal table,

n = 64

= 370

= / n = 38.54 64 = 4.8175

P(Z < z) = 86%

P(Z < z) = 0.86

P(Z < - 0.61) = 0.86

z = 1.08

Using z-score formula,

= z * +

= 1.08 * 4.8175 + 370

= 375.2029

Option b) is correct.