The Following Display from a TI-84 Plus Calculator Presents the Results

question 15

Multiple Choice

The following display from a TI-84 Plus calculator presents the results of a hypothesistest for the difference between two means. The sample sizes are $n _ { 1 } = 10 \text { and } n _ { 2 } = 15$

How many degrees of freedom did the calculator use?

• A) 20.308612
• B) -4.343066
• C) 19.308612
• D) 0.000158

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Definitions:

Population Mean

The average value of all the elements in a population, which is the total sum of all values divided by the number of values.

Margin of Error

A measure of the accuracy of a public opinion poll, representing the extent to which the results could vary from the true population values.

Sample Size

The count of observations or duplicates that are part of a statistical sample.

Quality Control

The process of ensuring that products and services meet consistent standards and requirements through various checks and measures.