Question

In a normally distributed data set of how long customers stay in your store, the mean is 44.8 minutes and the standard deviation is 2.6 minutes. Within what range would you expect 95% of your customers to stay in your store?

a2.6-44.8

b37.0-52.6

c42.2-47.4

d39.6-50.0

Answer 1

Here,

X ~ Normal(44.8, 2.6²)

To find $x_1$ and $x_2$ such that

P(Z 22-44.8 2.6 )-P(Z-L 44.8 = 0.95

One solution may be

and

Now,

and

ans-> d) 39.6 - 50.0