Question

Karri tests the charges of a random sample of 64 batteries from a large production run. The mean charge was 8.93 volts, and the process typically has a standard deviation of 0.2 volts. To see if the batch has a significantly different mean voltage from 9 volts, the value of the z-test statistic would be ___________.

Answer 1

The Z-statistic value is

Z = -2.33

Explanation:

Step(i):-

Random sample size 'n' = 64

mean of the sample 'x⁻ ' = 8.93 volts

standard deviation of the sample = 0.2 volts

mean of the Population"μ" = 9 volts

Step(ii):-

Z -statistic

`Z = (x^(-) -mean)/((S.D)/(√(n) ) )`

`Z = (8.93 -9)/((0.2)/(√(64) ) ) = -2.33`

Conclusion:-

The Z-statistic value is = -2.33