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.

· 24 seventh - graders estimated they spent less than an hour.
· 21 eighth - graders estimated they spent less than an hour.
· 36 eighth - graders were surveyed.
· 77 total students were surveyed.

fill in the missing values in the table below.

social media	more	less	total
8th grade
total

Explanation:

Step1: Find number of 8th - graders who spend more than an hour

We know that 36 eighth - graders were surveyed and 21 eighth - graders spend less than an hour. So the number of 8th - graders who spend more than an hour is $36 - 21=15$.

Step2: Find number of 7th - graders surveyed

The total number of students surveyed is 77 and 36 are 8th - graders. So the number of 7th - graders surveyed is $77 - 36 = 41$.

Step3: Find number of 7th - graders who spend more than an hour

We know that 24 seventh - graders spend less than an hour and 41 seventh - graders were surveyed. So the number of 7th - graders who spend more than an hour is $41 - 24 = 17$.

Step4: Find total number of students who spend more than an hour

The number of 7th - graders who spend more than an hour is 17 and the number of 8th - graders who spend more than an hour is 15. So the total number of students who spend more than an hour is $17+15 = 32$.

Step5: Find total number of students who spend less than an hour

The number of 7th - graders who spend less than an hour is 24 and the number of 8th - graders who spend less than an hour is 21. So the total number of students who spend less than an hour is $24 + 21=45$.

Answer:

Social Media	More	Less	Total
8th grade	15	21	36
Total	32	45	77