An electrician wants to know whether batteries made by two manufacturers have significantly different voltages. The voltage of 129

batteries from each manufacturer were measured. The population standard deviations of the voltage for each manufacturer are known. The results are summarized in the following table.

ManufacturerSample mean voltage (millivolts)Population standard deviation (millivolts)A151

4

B150

1

What type of hypothesis test should be performed?

What is the test statistic?

Does sufficient evidence exist to support the claim that the voltage of the batteries made by the two manufacturers is different at the =0.01

significance level?

Select

Right-tailed t-test

Left-tailed z-test

Left-tailed t-test

Two-tailed z-test

Select

No

Yes

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