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
1,918
20 - 29
3,968
30 - 39
2,846
40 - 49
747
50 - 59
347
60 - 69
317
70 - 79
96
To find the probability that a buyer on this website is aged 60-69, we need to calculate the proportion of buyers in the age group 60-69 out of the total number of buyers.
The total number of buyers is the sum of the number of buyers in each age group:
10-19: 1,918
20-29: 3,968
30-39: 2,846
40-49: 747
50-59: 347
60-69: 317
70-79: 96
Total number of buyers = 1,918 + 3,968 + 2,846 + 747 + 347 + 317 + 96 = 10,239
The number of buyers aged 60-69 is 317.
Probability of a buyer being aged 60-69 = Number of buyers aged 60-69 / Total number of buyers
= 317 / 10,239
Calculating this ratio, we find that the probability of a buyer on this website being aged 60-69 is approximately 0.031 or 3.1%.