Answer:

Step-by-step explanation:
1) we know that
Sally can paint the wall in 54 minutes
so
The 100% of the wall ------> she can paint in 54 minutes
by proportion
calculate how much is the percent of the work in 36 minutes

That means
Sally in 36 minutes can paint the 66.67% of the wall
2) Sally and Ethan work together, they can paint the wall in 36 minutes
so
Ethan in 36 minutes can paint (100%-66.67%)=33.33%
by proportion
Calculate how much time does it take for Ethan to paint the wall by herself

The answer is c because all you are doing here is subbing the variable r for 5b.
First, find the mean. You'll need it to compute the variance.

The variance of the sample is then computed with the formula

The standard deviation is the square root of the variance, so
The discount sales price would be $218
Answer: 9 in
Step-by-step explanation: