In Order to Estimate the Difference Between the Average Daily

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.