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Back to 7.3 Using the Central Limit Theorem

7.3 Exercise 8

Avg difficulty 2.5

Use the information in the example, but change the sample size to 144.

  1. Find P(20 < x ¯ \bar{x} < 30).
  2. Find P(Σx is at least 3000).
  3. Find the 75th percentile for the sample mean excess time of 144 customers.
  4. Find the 85th percentile for the sum of 144 excess times used by customers.

OpenStax Statistics, 7.3 Using the Central Limit Theorem, exercise 8

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