He is false the equation should be as follows
Answer:
$68,000
Step-by-step explanation:
we have to determine the total economic costs of going to college = ($40,000 x 2) + ($30,000 x 2) = $140,000
since we want to recover our "college investment" in 5 years or less, then we must earn at least $140,000 / 5 = $28,000 more per year
the minimum salary that we should earn after graduating = $40,000 (our current salary) + $28,000 (to recover college costs) = $68,000
To solve this
problem, we will have to make use of the z statistic. The formula for the z
score is given as:
z = (x – u) / s
where,
x is the sample value = more than $10.00
u is the sample mean = $8.22
s is the standard deviation = $1.10
Substituting the values into the equation to solve for z:
<span>z = (10 – 8.22) /
1.10</span>
z = 1.78 / 1.10
z = 1.62
We then look for the p value using the standard
distribution tables at the specified z score value = 1.62. Since this is a
right tailed test, therefore the p value is:
p = 0.0526
or
p = 5.26%
<span>Therefore there is a 5.26% probability that a household
spent more than $10.00</span>
