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Math Help - confidence interval

  1. #1
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    confidence interval

    A principal randomly slected 6 students to take an aptitude test, their scores were 83, 84.1, 83.5, 83.7, 84.1, and 73.5. construct a 90% confidence interval for the mean score for all students. Assume the population has a normal distribution.
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  2. #2
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    Quote Originally Posted by superman31 View Post
    A principal randomly slected 6 students to take an aptitude test, their scores were 83, 84.1, 83.5, 83.7, 84.1, and 73.5. construct a 90% confidence interval for the mean score for all students. Assume the population has a normal distribution.
    Compute the sample mean m and the unbiased estimate from the sample of the population SD s.

    Then the interval you require is: (m-\lambda s, m+\lambda s) where \lambda is the 95 \% point for the cumulative t-distribution with n=5 degrees of freedom.

    CB
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