Liliana wants to start a seventh-grade computer club at Hamden Middle School. She surveyed 20 seventh-grade students at the town park. She asked each student how many hours they spend on their computers each week. She obtained the following results. 8, 15, 0, 11, 12, 13, 16, 13, 0, 4, 17, 14, 30, 13, 5, 12, 1, 13, 12, 21

What is the ratio of the total number of students who used their computers to the total number of students surveyed?
StartFraction 2 over 20 EndFraction or StartFraction 1 over 10 EndFraction
StartFraction 2 over 18 EndFraction or StartFraction 1 over 9 EndFraction
StartFraction 18 over 20 EndFraction or StartFraction 9 over 10 EndFraction
StartFraction 18 over 2 EndFraction or StartFraction 9 over 1 EndFraction

Liliana surveyed 20 students that how many hours they spend on their computers each week.

The results are as follows

8, 15, 0, 11, 12, 13, 16, 13, 0, 4, 17, 14, 30, 13, 5, 12, 1, 13, 12, 21

In the above results 2 students did not use computers out of 20 students.

Therefore, The total number of students who used their computers = 20 - 2 = 18

So the ratio would be 18 : 20 or 9 : 10

b: |12 – x| ≤ 0.25

step-by-step explanation:      

let x be the possible lengths in inches, of the ribbons jaime cut.

we have been given that jaime is cutting strips of ribbon for a project. he tries to cut each piece to be 12 inches long, but sometimes he cuts it too long or too short by as much as 0.25 inch.  

we can represent this information in an inequality as:

by the definition of absolute value function we will get,

upon combining our inequalities we will get,

therefore, the inequality   describes all the possible lengths (x), in inches, of the ribbons jaime cut.

step-by-step explanation: