What Is a Confidence Interval?

Calculation: (Two-Sample Mean)

given:

$n_1 = 35$

$\bar{x_1} = 100$

$\sigma_1^{2} = 3^{2} = 9$

---

$n_2 = 56$

$\bar{x_2} = 85$

$\sigma_2^{2} = 4^{2} = 16$

---

Find the 99% confidence interval.