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In: Statistics and Probability

Students in a different statistics class were asked to report the age of their mothers when...

Students in a different statistics class were asked to report the age of their mothers when they were born. Here are the summary statistics:

Sample size: 28     sample mean: 29.643 years         sample stDev: 4.564 years

  1. Calculate the standard error of this sample mean.
  2. Determine and interpret a 90% confidence interval for the mother’s mean age (at student’s birth) in the population of all students at the college.
  3. How would a 99% confidence interval compare to the 90% confidence interval in terms of its midpoint and half-width?
  4. Would you expect 90% of the ages in the sample to be in the 90% confidence interval? Explain why or why not.

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