Question

A battery manufacturer was considering changing suppliers for a particular part. The purchasing manager required that the average cost of the part be less than or equal to $32 in order to stay within budget. A sample of the 32 initial deliveries had a Mean of the new product upgrade price of $28 with an estimated Standard Deviation of $3. Based on the data provided, the Z value for the data assuming a Normal Distribution is?

A) 0.67
B) 1.33
C) 2.67
D) 4.33

Answer 1

1.33

Explanation:

Given that a battery manufacturer was considering changing suppliers for a particular part. The purchasing manager required that the average cost of the part be less than or equal to $32 in order to stay within budget.

Sample size n =32

Mean of sample = 28

Std deviation of sample s= 3

Std error of the mean =
`(s)/(√(n) ) \\=0.53033`

Mean difference = 28-32 = -4

Test statistic Z = mean difference/std deviation

=
`|(-4)/(3)| \\=1.33`