Using the Central Limit Theorem · Try It 2
Use the information in, but change the sample size to 144.
(a) Find P(20 < < 30).
(b) Find P(Σx is at least 3,000).
(c) Find the 75^th percentile for the sample mean excess time of 144 customers.
(d) Find the 85^th percentile for the sum of 144 excess times used by customers.
Its source prints no answer for this problem, so there's nothing to check against.
OpenStax, Introductory Statistics 2e · §7.3 Using the Central Limit Theorem · Try It 2
No hints for this one.
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