We Are Interested in Comparing the Average Supermarket Prices of Two

question 84

Multiple Choice

We are interested in comparing the average supermarket prices of two leading colas. Our sample was taken by randomly selecting eight supermarkets and recording the price of a six-pack of each
Brand of cola at each supermarket. The data are shown in the following table: If the problem above represented a paired difference, what assumptions are needed for a
Confidence interval for the mean difference to be valid?

• A)The population variances are equal.
• B)The population of paired differences has an approximately normal distribution.
• C)The samples were independently selected from each population.
• D)All of the above are needed.

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Definitions:

Tukey's Multiple Comparison

A statistical test used to find the differences between means in a set of data, controlling the error rate when making several comparisons.

Studentized Range Statistic

A measure used in statistics to identify outliers in a data set, calculated by dividing the range by an estimate of the standard deviation.

Critical Value

A critical value is a point on the distribution curve that separates the area where the null hypothesis is accepted from the area where it is rejected in hypothesis testing.

Sample Sizes

Measurements or quantities of observations used in a statistical sample, representing a portion of the population under study.