Use of the internet for shopping is increasing dramatically, but still is somewhat age dependent. When a popular web site that sells books asked the age of users who bought products from them over the internet, they obtained the following data. What is the probability that a buyer on this web site is aged 60-69?
Age Group Number
10 - 19
1,915
20 - 29
3,719
30 - 39
2,983
40 - 49
767
50 - 59
445
60 - 69
253
70 - 79
64
To find the probability that a buyer on this web site is aged 60-69, we need to calculate the proportion of buyers in the 60-69 age group out of the total number of buyers.
The total number of buyers is the sum of the number of buyers in each age group:
Total number of buyers = 1,915 + 3,719 + 2,983 + 767 + 445 + 253 + 64 = 10,146
The number of buyers in the 60-69 age group is 253.
Therefore, the probability that a buyer on this web site is aged 60-69 is:
P(60-69) = Number of buyers in the 60-69 age group / Total number of buyers
P(60-69) = 253 / 10,146
P(60-69) ≈ 0.025 or 2.5%