Calculating the Mean from Frequency Tables

A survey of household pets shows: 0 pets (frequency 5), 1 pet (frequency 12), 2 pets (frequency 8). Calculate the mean number of pets.

Products are 0, 12, and 16. Sum of products is 28. Sum of frequencies is 25. Mean is 28 divided by 25, which equals 1.12 pets.

In a quiz scored out of 5: score 3 (frequency 4), score 4 (frequency 10), score 5 (frequency 6). Calculate the mean score.

Products are 12, 40, and 30. Sum of products is 82. Sum of frequencies is 20. Mean is 82 divided by 20, which equals 4.1.

Find the relative frequency of getting a score of 4 in the quiz from the previous question.

Divide the frequency of 10 by the total count of 20, which gives 0.50 or 50 percent.

A store records daily shoe sales: 5 pairs (2 days), 10 pairs (5 days), 15 pairs (3 days). Find the average number of pairs sold per day.

Products are 10, 50, and 45. Sum of products is 105. Sum of frequencies is 10 days. Mean is 105 divided by 10, which equals 10.5 pairs per day.

A student adds three rows of values (10, 20, 30) with frequencies (1, 2, 7) and divides the total product of 310 by 3 to get 103.3. What was their error and what is the correct mean?

The student divided by the number of rows instead of the sum of frequencies. The total frequency is 10, so the correct mean is 310 divided by 10, which equals 31.

Grouped data shows travel times: 0 to 10 minutes has midpoint 5 (frequency 4), 10 to 20 minutes has midpoint 15 (frequency 6). Estimate the mean travel time.

Products are 20 and 90. Sum of products is 110. Sum of frequencies is 10. Estimated mean is 110 divided by 10, which equals 11 minutes.