Purchase Solution

Confidence interval for a population proportion

Not what you're looking for?

Ask Custom Question

The lifetime of a certain brand of battery is known to have a standard deviation of 11.3 hours. Suppose that a random sample of 90 such batteries has a mean lifetime of 33.4 hours. Based on this sample, find a 95% confidence interval for the true mean lifetime batteries of this brand. What is the lower limit of the 95% confidence level? What is the upper limit?

Purchase this Solution

Solution Summary

This solution shows step-by-step how to construct and interpret a confidence interval for a population proportion.

Solution Preview

How to find upper and lower limit of a confidence level
The lifetime of a certain brand of battery is known to have a standard deviation of 11.3 hours. Suppose that a random sample of 90 such batteries has a mean lifetime of 33.4 hours. Based on this sample, find a 95% confidence interval for the true mean lifetime ...

Purchase this Solution


Free BrainMass Quizzes
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.

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.