# Finding the mean and the sample size

Not what you're looking for?

A bank wants to estimate the mean dollars that each credit card holder will spend each month. It would like to be within + or - $10 of the true mean with a 98% condfidence level. The standard deviation is $500. How many card holders should be sampled?

##### Purchase this Solution

##### Solution Summary

A bank wants to estimate the mean dollars that each credit card holder will spend each month. It would like to be within + or - $10 of the true mean with a 98% condfidence level. The standard deviation is $500. How many card holders should be sampled?

##### Solution Preview

Since the population standard deviation is known, we use z value for calculation.

The two-tailed 98% z value is z = 2.33

Let N = sample size

The confidence interval ...

##### Purchase this Solution

##### Free BrainMass Quizzes

##### 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.

##### Terms and Definitions for Statistics

This quiz covers basic terms and definitions of statistics.

##### 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.