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

7.2 Exercise 5

Avg difficulty 2.5

The mean number of minutes for app engagement by a tablet user is 8.2 minutes. Suppose the standard deviation is one minute. Take a sample size of 70.

  1. What are the mean and standard deviation for the sums?
  2. Find the 95th percentile for the sum of the sample. Interpret this value in a complete sentence.
  3. Find the probability that the sum of the sample is at least 10 hours.

OpenStax Statistics, 7.2 The Central Limit Theorem for Sums (Optional), exercise 5

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