Question

The average credit card debt for college seniors is $3120. The debt is normally distributed with standard deviation of $1100. Find P35.

Answer 1

Solution :

Using standard normal table,

P(Z < z) = 35%

P(Z < -0.39) = 0.35

z = -0.39

Using z-score formula,

x = z * $\sigma$ + $\mu$

x = -0.39 * 1100 + 3120 = 2691

P35 = 2691