Answer:
About 95% of households have an income over $54,550
Step-by-step explanation:
95% is a probability of around 0.95
So we start by calculating the z-score with a probability of 0.95
We can use the standard normal distribution table for this
the z-score is -1.645
Mathematically;
z-score = (x-mean)/SD
-1.645 = (x-71,000)/10,000
10,000 * -1.645 = x-71,000
-16450 = x - 71000
x = 71,000 - 16450
x = 54,550
