Question

D Question 17 5 pts From a sample of 100 stores in your area you have found that the mean price of a gallon of milk is $3.16. The mean nationally is $3.21 with a standard deviation of $0.19. Calculate the Z obtained. Round to the second decimal place.

Answer 1

Solution :

Given that ,

mean = $\mu$ = 3.16

standard deviation = $\sigma$ = 0.19

n = 100

$\mu$$\bar x$ = 3.16

$\sigma$$\bar x$ =$\sigma$  / $\sqrt$ n= 0.19/ $\sqrt$ 100=0.019

using a score formual z = ($\bar x$ -$\mu$$\bar x$ ) / $\sigma$ $\bar x$

=3.21-3.16/0.019

=2.63