Let's understand how to solve the given problem step-by-step.
1. Total Number of Students Surveyed:
Liliana surveyed 20 students. So, the total number of students is:
[tex]\[
\text{Total students surveyed} = 20
\][/tex]
2. Hours Students Spent on Computers:
The given hours each student spends on computers each week are:
8, 15, 0, 11, 12, 13, 16, 13, 0, 4, 17, 14, 30, 13, 5, 12, 1, 13, 12, 21
3. Number of Students Who Used Their Computers:
We need to count how many students used their computers (students who spent more than 0 hours). Let's count those:
- 8, 15, 11, 12, 13, 16, 13, 4, 17, 14, 30, 13, 5, 12, 1, 13, 12, 21
These are 18 students.
Therefore:
[tex]\[
\text{Number of students using computers} = 18
\][/tex]
4. Form the Ratio:
The ratio of the number of students who used their computers to the total number of students surveyed is then:
[tex]\[
\frac{\text{Number of students using computers}}{\text{Total students surveyed}} = \frac{18}{20}
\][/tex]
5. Simplify the Ratio:
To simplify the ratio, find the greatest common divisor (GCD) of 18 and 20, which is 2. Divide both the numerator and the denominator by their GCD:
[tex]\[
\frac{18 \div 2}{20 \div 2} = \frac{9}{10}
\][/tex]
So, the ratio of the total number of students who used their computers to the total number of students surveyed is:
[tex]\[
\frac{18}{20} \text{ or } \frac{9}{10}
\][/tex]
Therefore, the correct choice is:
[tex]\[
\frac{18}{20} \text{ or } \frac{9}{10}
\][/tex]
The final answer is:
[tex]\[
\frac{18}{20} \text{ or } \frac{9}{10}
\][/tex]
