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In a Very Large School District, Student Records Have Been

question 29

Essay

In a very large school district, student records have been kept in three distinct data bases, one each for elementary, middle, and high school. The district now has a new data base and wishes to correct any original data entry errors. To allocate enough secretarial time to this task, an estimate of the proportion of records that contain errors must be made. Initial estimates are that there are fixable errors in about 15% of the records.
A) Using 15% as an initial estimate of the percentage of records with errors, compute the sample size required to estimate the true proportion of records with errors within .025 with 95% confidence.
B) Suppose the school district did not have an initial estimate of p . In a few sentences, explain how your procedure for choosing a samples size would differ from your solution in part (a). (Do NOT recalculate a new estimate of the necessary sample size!)

Definitions:

Level Of Significance

The threshold for rejecting the null hypothesis in a statistical test, often denoted by alpha and representing the risk of a Type I error.

One-Tail

It refers to tests of significance that determine if there is a relationship or a difference in only one direction, either greater than or less than, but not both.

Test Statistic

A calculated value used in statistical hypothesis testing to determine whether to reject the null hypothesis.

Level Of Significance

The probability of rejecting the null hypothesis in a statistical test when it is actually true; a threshold for determining the statistical significance of a result.