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    Hypothesis Testing and Confidence Interval

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    Based on data from USA Today, tax returns include an option of designating $3 for presidential election campaigns, and it does not cots the taxpayer anything to make that designation. In a simple random sample of 250 taxpayer returns from 1976, 27.6% of the returns designated the $3 for the campaign. In a simple random of 300 recent returns, 7.3% of the returns designated the $3 for the campaign.
    Construct a 98% confidence interval estimate for the difference of the percentages of returns designating the $3 for the campaign in 1976 and that of the recent returns. What conclusion does the confidence interval suggest?

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    https://brainmass.com/statistics/correlation-and-regression-analysis/hypothesis-testing-confidence-interval-613355

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    Based on data from USA Today, tax returns include an option of designating $3 for presidential election campaigns, and it does not cots the taxpayer anything to make that designation. In a simple random sample of 250 taxpayer returns from 1976, 27.6% of the returns designated the $3 for the campaign. In a simple random of 300 recent returns, 7.3% of the returns designated the $3 for the campaign.
    Construct a 98% confidence interval estimate for the difference of the percentages of returns designating the $3 for the campaign in 1976 and that of the recent returns. What conclusion does the confidence interval suggest?
    Answer
    98% confidence interval is given by,

    Confidence Interval Estimate
    of the Difference Between Two Proportions

    Data
    Confidence Level 98%

    Intermediate Calculations
    Z Value -2.3263
    Std. Error of the Diff. between two Proportions 0.0320
    Interval Half Width 0.0745

    Confidence Interval
    Interval Lower Limit 0.1285
    Interval Upper Limit 0.2775

    Since the confidence interval does not include zero, we can conclude that there is significant difference ...

    Solution Summary

    The solution provides step by step method for the calculation of confidence interval and testing of hypothesis. Formula for the calculation and Interpretations of the results are also included.

    $2.19

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