Answer: 0.345
Step-by-step explanation:
Given : The incomes of families in Newport Harbor are normally distributed with Mean :
and Standard deviation : 
Samples size : n=4
Let x be the random variable that represents the incomes of families in Newport Harbor.
The z-statistic :-

For x= $800,000

By using the standard normal distribution table , we have
The probability that the average income of these 4 families exceeds $800,000 :-

Hence, the probability that the average income of these 4 families exceeds $800,000 =0.345
His dog will drink 112oz a week
It is 14 cups
It is 5.81 pints
It is 3.5 quarts
Intersection
x - 7,0
y - 0,-4