In Testing the Hypotheses:
H₀ $\mu$ ₁ - $\mu$ ₂ = 0
H_A

In testing the hypotheses:
H₀: $\mu$ ₁ - $\mu$ ₂ = 0
H_A: $\mu$ ₁ - $\mu$ ₂ $\neq$ 0,
two random samples from two normal populations produced the following statistics:
n₁ = 51, x₁-bar = 35, s₁ = 28.
n₂ = 40, x₂-bar = 28, s₂ = 10.
Assume that the two population variances are different.
a. Estimate with 95% confidence the difference between the two population means.
b. Explain how to use this confidence interval for testing the hypotheses.