Question

A survey asked a random sample of students if they estimated they spent more or less than an hour a day on social media. Results are shown in the table below, but some values are missing. Fill in the missing values.
Social Media
Grade More Less Total
7th grade
15 27
8th grade
19
Total
68

Answer 1

Filled table:

Grade More Less Total
7th 12 15 27
8th 22 19 41
Total 34 34 68

Work:
- 7th more = 7th total − 7th less = 27 − 15 = 12.
- Total less = 15 + 19 = 34, so total more = 68 − 34 = 34.
- 8th more = total more − 7th more = 34 − 12 = 22.
- 8th total = 22 + 19 = 41.