Two random samples are selected from two independent populations. A summary of the samples sizes, sample means, and sample standard deviations is given below:

$$\begin{array}{lll} n_1 = 37, & \bar{x}_1 = 51.8, & s_1 = 6 \\ n_2 = 46, & \bar{x}_2 = 77.9, & s_2 = 10.5 \\ \end{array}$$

Find a 93% confidence interval for the difference $\mu_1 - \mu_2$ of the means, assuming equal population variances.

Confidence Interval =