Ask Question
2 April, 13:30

A random sample of 28 male runners showed that they spent an average of 22 hours a week preparing for races. The standard deviation of the sample was 2 hours. Find the 95% confidence interval.

+2
Answers (1)
  1. 2 April, 13:44
    0
    Step-by-step explanation:

    We want to determine a 95% confidence interval for the average time spent by male runners in a week in preparing for races.

    Number of sample, n = 28

    Mean, u = 22 hours

    Standard deviation, s = 2 hours

    For a confidence level of 95%, the corresponding z value is 1.96. This is determined from the normal distribution table.

    We will apply the formula

    Confidence interval

    = mean ± z * standard deviation/√n

    It becomes

    22 ± 1.96 * 2/√28

    = 22 ± 1.96 * 0.378

    = 22 ± 0.741

    The lower end of the confidence interval is 22 - 0.741 = 21.259

    The upper end of the confidence interval is 22 + 0.741 = 22.741
Know the Answer?
Not Sure About the Answer?
Get an answer to your question ✅ “A random sample of 28 male runners showed that they spent an average of 22 hours a week preparing for races. The standard deviation of the ...” in 📙 Mathematics if there is no answer or all answers are wrong, use a search bar and try to find the answer among similar questions.
Search for Other Answers