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    Question: An article contained the following observations on degree of polymerization for paper specimens for which viscosity times concentration fell in a certain middle range.

    Degree: 429 421 421 422 425 427 431 436 437 439 446 447 448 452 453 463 465

    a) Calculate a two-sided 98% confidence interval for true average degree of polymerization. What is the lower limit?

    b) Calculate a two-sided 98% confidence interval for true average degree of polymerization. What is the upper limit?

    c) Calculate a two-sided 95% confidence interval for true average degree of polymerization (as did the authors of the article).
    What is the lower limit of this confidence interval?

    d) Calculate a two-sided 95% confidence interval for true average degree of polymerization (as did the authors of the article).
    What is the upper limit of this confidence interval?

    e) Does the 95% confidence interval suggest that 440 is a plausible value for true average degree of polymerization?

    f) Does the 95% confidence interval suggest that 450 is a plausible value?

    Give your answers correct to three decimal places.

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    Solution Preview

    Question: An article contained the following observations on degree of polymerization for paper specimens for which viscosity times concentration fell in a certain middle range.

    Degree: 429 421 421 422 425 427 431 436 437 439 446 447 448 452 453 463 465

    a) Calculate a two-sided 98% confidence interval for true average degree of polymerization. What is the lower limit?

    b) Calculate a two-sided 98% confidence interval for true average degree of polymerization. What is the upper limit?

    c) Calculate a two-sided 95% confidence interval for true average degree of polymerization (as did the authors of the article).
    What is the lower limit of this confidence interval?

    d) Calculate a two-sided 95% confidence interval for true average degree of polymerization (as did the authors of the article).
    What is the upper limit of this confidence interval?

    e) Does the 95% confidence interval suggest that 440 is a plausible value for true average degree of polymerization?

    f) Does the 95% confidence interval suggest that 450 is a plausible value?

    Answer:
    Calculate the mean and standard deviation of the sample

    Mean and standard deviation

    X= X 2 =
    ...

    Solution Summary

    Calculates Confidence interval for true average degree of polymerization.

    $2.49

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