Suppose the number of gallons of gasoline per day used by a car is normally distributed with a mean of 2.2 gallons and a standard deviation of 1.2 gallons.

What is the difference in gallons per day used by a car with a z-score of 3 and another car that has a z-score of 0?

1.2
2.6
3.6
4.6

Question

Suppose the number of gallons of gasoline per day used by a car is normally distributed with a mean of 2.2 gallons and a standard deviation of 1.2 gallons.

What is the difference in gallons per day used by a car with a z-score of 3 and another car that has a z-score of 0?

1.2
 2.6
 3.6
 4.6

Vocaloid · Answer

we work backwards from the z-score formula to find what the two gallons per day numberse are

Vocaloid · Answer

3 = (x-2.2)/1.2

0 = (y - 2.2)/1.2

solve for x and y, then subtract x - y to find the answer