Answer:
68/99
Step-by-step explanation:
.68686868686 repeating
Let x= .68686868668repeating
Multiply by 100
100x = 68.686868686repeating
Subtract x = .68686868repeating from this equation
100x = 68.686868686repeating
-x = .68686868repeating
------------------------------------------
99x = 68
Divide each side by 99
99x / 99 = 68/99
x = 68/99
Answer
Q1- c
Q2-c
Q3-d
Q4-b
Q5-a
The difference in gallons per day used is 3.6.
The formula to calculate a z-score is:

,
where X is the value used to calculate the score, μ is the mean and σ is the standard deviation. We have the z-scores so we must work backward:

For both equations, we will cancel the 1.2 by multiplying both sides:

Now we will cancel 2.2 from both equations by adding it to both sides:
3.6+2.2=X-2.2+2.2 and 0+2.2=X-2.2+2.2
5.8=X and 2.2=X
The difference in gas used per day would be given by
5.8-2.2 = 3.6.