Answer:
<h2>
$5.03</h2>
Step-by-step explanation:
Given data
Sample Mean (M): $48.77
Sample Size (n): 20
Standard Deviation (σ) : $17.58
Confidence Level: 80%
we know that z*-Values for 80% Confidence Levels is 1.28
the expression for margin of error is given bellow\
MOE= z*σ/√n
We can now substitute into the expression and solve for the MOE as
MOE= 1.28*17.58/√20
MOE= 22.502/4.47
MOE= 22.502/4.47
MOE= 5.03
The margin of error for a 80 % confidence interval is $5.03
X is 5. Hope this helps:)
Set up a proportion like this

=
So your proportion would be:

We put x for offices because they are asking for the number o offices a crew can paint in 12 hours, and also we don't know the number of offices they can paint in 12 hours
so we cross multiply and we get
6x=60, we got 60 by multiplying 12 and 5
Now we divide both sides by 6 and we get
x=10
S the crew can paint 10 offices in 12 hours.
The percent decrease is 80% or 80 percent