a survey asked a random sample of students if they estimated they spent more or less than an hour a day on…
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 more less total 7th grade 8th grade 16 27 total 34 66
Answer
Explanation:
Step1: Find the number of 8th - grade students who spend less time
Since the total number of 8th - grade students is 27 and 16 spend more time, then the number of 8th - grade students who spend less time is (27 - 16=11).
Step2: Find the total number of students who spend less time
Since the total number of students is 66 and 34 spend more time, then the total number of students who spend less time is (66 - 34 = 32).
Step3: Find the number of 7th - grade students who spend more time
Since the total number of students who spend more time is 34 and 16 are 8th - grade students, then the number of 7th - grade students who spend more time is (34 - 16=18).
Step4: Find the number of 7th - grade students who spend less time
Since the total number of students who spend less time is 32 and 11 are 8th - grade students, then the number of 7th - grade students who spend less time is (32 - 11 = 21).
Step5: Find the total number of 7th - grade students
The total number of 7th - grade students is the sum of 7th - grade students who spend more time and 7th - grade students who spend less time. So it is (18+21 = 39).
Answer:
| Social Media | More | Less | Total |
|---|---|---|---|
| 7th grade | 18 | 21 | 39 |
| 8th grade | 16 | 11 | 27 |
| Total | 34 | 32 | 66 |