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Back to 7.2 The Central Limit Theorem for Sums (Optional)

7.2 Exercise 31

Avg difficulty 2.5


Use the following information to answer the next three exercises: A market researcher analyzes how many electronics devices customers buy in a single purchase. The distribution has a mean of three with a standard deviation of 0.7. She samples 400 customers.

What is the z-score for Σx = 840?

OpenStax Statistics, 7.2 The Central Limit Theorem for Sums (Optional), exercise 31

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