Purchase Solution

Confidence Interval and Sample Size Calculations

Not what you're looking for?

Ask Custom Question

1. Of 300 people waiting lunch at a department store cafeteria, 102 had dessert. What is the confidence associated with a Rao score interval of length .1 (i.e., margin of error .05)?

2. Calculate the sample size necessary to estimate the proportion of drivers that exceed the spend limit on a stretch of a road between Bakersfield and Los Angeles within a margin of error of .04 with a 99% confidence.

3. How large a sample is necessary to estimate a politician's approval rating with a margin of error of 3.5% if we want 90%, 95%, and 99% confidence?

See the attached file.

Attachments
Purchase this Solution

Solution Summary

The solution calculates the confidence interval and sample size of the given problem.

Solution Preview

Please refer to the attachment.

1. Of 300 people waiting lunch at a department store cafeteria, 102 had dessert. What is the confidence associated with a Rao score interval of length .1 (i.e., margin of error .05)?
Solution:
The margin of error, for confidence interval for proportion, is given as follows:
E=zα2 p1−pn
Given:
Proportion of Success, p=102300=0.34
Sample Size, n=300
Margin of ...

Purchase this Solution


Free BrainMass Quizzes
Terms and Definitions for Statistics

This quiz covers basic terms and definitions of statistics.

Know Your Statistical Concepts

Each question is a choice-summary multiple choice question that presents you with a statistical concept and then 4 numbered statements. You must decide which (if any) of the numbered statements is/are true as they relate to the statistical concept.

Measures of Central Tendency

This quiz evaluates the students understanding of the measures of central tendency seen in statistics. This quiz is specifically designed to incorporate the measures of central tendency as they relate to psychological research.

Measures of Central Tendency

Tests knowledge of the three main measures of central tendency, including some simple calculation questions.