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

Answer:

The Z-statistic value is

                  Z = -2.33

Step-by-step 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

             $Z = \frac{x^{-} -mean}{\frac{S.D}{\sqrt{n} } }$

             $Z = \frac{8.93 -9}{\frac{0.2}{\sqrt{64} } } = -2.33$

Conclusion:-

The Z-statistic value is  = -2.33