Explore BrainMass
Share

Hypothesis Testing and Confidence Interval

This content was STOLEN from BrainMass.com - View the original, and get the already-completed solution here!

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?

© BrainMass Inc. brainmass.com October 17, 2018, 1:22 pm ad1c9bdddf
https://brainmass.com/statistics/correlation-and-regression-analysis/hypothesis-testing-confidence-interval-613355

Attachments

Solution Preview

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
Similar Posting

One-Sample Hypothesis Test Confidence Intervals

One-Sample Hypothesis Test Confidence Intervals

Take a random sample and perform a t-test against a population mean (no time series for any parts of this project.) Test a hypothesis about a population mean. Besides the instructions above, explain what assumptions you made. Note: n must be between 15 to 20! Use no other sample sizes.

Use the same data as 1a and develop a 90% confidence interval and a 95% confidence interval for the population mean. Contrast this to 1a. What additional information or insight did this provide you over the traditional hypothesis testing.

View Full Posting Details