Back to 7.3 Using the Central Limit Theorem

7.3 Exercise 53

Avg difficulty 2.5


For each problem, wherever possible, provide graphs and use a calculator.

NeverReady batteries has engineered a newer, longer-lasting AAA battery. The company claims this battery has an average life span of 17 hours with a standard deviation of 0.8 hours. Your statistics class questions this claim. As a class, you randomly select 30 batteries and find that the sample mean life span is 16.7 hours. If the process is working properly, what is the probability of getting a random sample of 30 batteries in which the sample mean life span is 16.7 hours or less? Is the company’s claim reasonable?

OpenStax Statistics, 7.3 Using the Central Limit Theorem, exercise 53

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