7.2 is the answer i hope this helps!
There are a total of 68 cars in the parking lot (sum of all values on the table).
Selecting blue OR a chevy, means all blue and all chevies are valid choices...there are 7+9+8+7+5 (blue cars and chevy cars) = 36:
36/68 = 9/17
Selecting blue AND a chevy - There are 8 blue chevies:
<span>8/68= </span>2/17
GIVEN that the car is blue means we're <em>only selecting from </em>the 7+9+8 = 24 blue cars on the lot which are chevies...and there are 8 blue chevies:
8/24 = 1/3
C) because it equals each other
The sum of the m numbers divided by m (which is the average) equals n^2. Then, the sum of the m numbers equals mn^2.
The sum of the n numbers divided by n (which is the average) equals m^2. Then, the sum of the n numbers equals nm^2.
The average of m+n numbers which is the sum of the m numbers plus the sum of the n numbers divided by (m+n) equals (mn^2+nm^2)/(m+n). This is mn(n+m)/(m+n). Then the factor (m+n) can be ruled out and the result is mn.