In Order to Estimate the Difference Between the Average Daily

question 94

Short Answer

In order to estimate the difference between the average daily sales of two branches of a department store, the following data has been gathered.
$\begin{array}{lcc}&\text { Downtown Store}&\text {North Mall Store }\\\text { Sample size } & \mathrm{n}_{1}=23 \text { days } & \mathrm{n}_{2}=26 \text { days } \\\text { Sample mean in } \$ 1,000) & =37 & =34 \\\text { Sample standard deviation in } \$ 1,000) & \mathrm{S}_{1}=4 & \mathrm{~S}_{2}=5\end{array}$

a. Determine the point estimate of the difference between the means.
b. Determine the degrees of freedom for this interval estimation.
c. Compute the margin of error.
d. Develop a 95% confidence interval for the difference between the two population means.

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Definitions:

Earth's Surface

The outermost layer of the Earth, consisting of the crust and the upper part of the mantle.

Estuaries

Coastal water bodies where freshwater from rivers meets and mixes with saltwater from the ocean, creating unique and richly biodiverse environments.

Salinity

The measure of the amount of dissolved salts in a given amount of liquid.