The Head Librarian at the Library of Congress Has Asked

question 130

Multiple Choice

The head librarian at the Library of Congress has asked her assistant for an interval estimate of the mean number of books checked out each day.The assistant provides the following interval estimate: from 740 to 920 books per day.If the head librarian knows that the population standard deviation is 150 books checked out per day,and she asked her assistant for a 95% confidence interval,approximately how large a sample did her assistant use to determine the interval estimate?

• A)125
• B)13
• C)11
• D)4

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Definitions:

Null Hypothesis

In testing, it is the presumption that no effect or no difference exists in the population, serving as the hypothesis that is formally tested.

P-value

A measure in statistical hypothesis testing that helps in determining the significance of results, indicating the probability of observing the data if the null hypothesis is true.

Simple Random Sample

A sample drawn in such a way that every member of the population has an equal chance of being selected.

Degrees Of Freedom

The number of independent values or quantities which can be assigned to a statistical distribution, often related to the number of values in the final calculation of a statistic that are free to vary.