Author Question: In developing an interval estimate of the population mean, if the population standard deviation is ... (Read 123 times)

jasdeep_brar

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In developing an interval estimate of the population mean, if the population standard deviation is unknown _____.
 a. it is impossible to develop an interval estimate
  b. a sample proportion can be used
  c. the sample standard deviation and t distribution can be used
  d. None of the answers is correct.

Question 2

The life expectancy of a particular brand of tire is normally distributed with a mean of 40,000 and a standard deviation of 5,000 miles. What is the probability that a randomly selected tire will have a life of at least 30,000 miles?
 a. .4772
  b. .9772
  c. .0228
  d. None of the answers is correct.



HandsomeMarc

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Answer to Question 1

c

Answer to Question 2

b



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