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MediumConfidence intervals
OpenStax, Introductory Statistics 2e §8.2 A Single Population Mean using the Student t Distribution · Exercise 33 · Statistics · Confidence intervals

A Single Population Mean using the Student t Distribution · Exercise 33

In a recent sample of 84 used car sales costs, the sample mean was $6,425 with a standard deviation of $3,156. Assume the underlying distribution is approximately normal.

(a) Which distribution should you use for this problem? Explain your choice.
(b) Define the random variable in words.
(c) Construct a 95% confidence interval for the population mean cost of a used car.
(a) State the confidence interval.
(b) Sketch the graph.
(c) Calculate the error bound.
(d) Explain what a “95% confidence interval” means for this study.

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OpenStax, Introductory Statistics 2e · §8.2 A Single Population Mean using the Student t Distribution · Exercise 33

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