Question

A battery manufacturer claims that the batteries used in their electronic games will last an average of 36 hours. To certify this average, 12 batteries are tested each month. Calculate the t-value for a sample of 12 batteries that has a sample mean of 32.5 hours and a sample standard deviation of 5 hours. Assume the distribution of battery lives to be approximately normal, i.e. rules of symmetry apply. Round answer to 4 significant figures in the format: -1.234

The battery manufacturer in the above problem considers its claim of an average lifetime of 36 hours valid if the calculated t-value falls between –t(0.025) and +t(0.025). What are the degrees of freedom for this problem? Round answer to 2 significant figures in the format: 12

Answer 1

We are provided with the following information

The formula for a t-statistic is

The degree of freedom for this problem are:

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