Answer:
The distribution of probability is valid if sum of all the probabilities equals to 1.
Explanation:
Age Range   Midpoint   Percent of super shopper
18-28 Â Â Â Â Â Â Â Â 23 Â Â Â Â Â Â Â Â 7%
29-39 Â Â Â Â Â Â Â 34 Â Â Â Â Â Â Â Â 44%
40-50 Â Â Â Â Â Â Â 45 Â Â Â Â Â Â Â Â 24%
51-61 Â Â Â Â Â Â Â Â 56 Â Â Â Â Â Â Â Â 14%
61 and over    67         11%
∑p(x) = P (x1)
The distribution of the shoppers is valid as the sum of all the probabilities equals to 1.
∑p(x) : 0.7 + 0.44 + 0.24 + 0.14 + 0.11 = 1
