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    Confidence interval for mean

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    5. A researcher wants to estimate the mean number of hours (mu) ; children watch television per day. A sample of 38 children is taken. The sample mean is 6.8 hours with a sample standard deviation of 1.1 hours.

    a. Find the 90% confidence interval for mean (mu).
    b. Find the 95% confidence interval for mean (mu).

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    Solution Preview

    5. Data:
    Sample mean= Xbar = 6.8 hours
    Sample Standard deviation = 1.1 hours
    Sample size = 38
    Population standard deviation (Known, Not Known) = Not Known.

    No. of tails = 2 (as we are calculating the confidence interval).
    Since sample size is more than 30 use normal distribution.
    Thus, we use z distribution.

    a. Find the 90% confidence interval ...

    Solution Summary

    Computes the the 90% and 95% confidence interval for mean number of hours children watch television per day. Excel file is included.

    $2.19

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