Question

in a survey, 18 people reported the number of hours they spent on the internet last week. their responses are given below. complete the grouped relative frequency distribution for the data. (note that we are using a class width of 6.) write each relative frequency as a decimal rounded to the nearest hundredth, not as a percentage. number of hours: 12 21 11 22 15 17 13 10 24 9 6 18 19 9 16 24 9 18

Explanation:

Step1: Count data in each class

For the class 2 - 7, the values in this range are 6. So the frequency $f_1 = 1$.

Step2: For class 8 - 13

The values in this range are 12, 11, 10, 13. So the frequency $f_2=4$.

Step3: For class 14 - 19

The values in this range are 15, 17, 18, 19, 16, 18. So the frequency $f_3 = 6$.

Step4: For class 20 - 25

The values in this range are 21, 22, 24, 24. So the frequency $f_4 = 4$.

Step5: Calculate total frequency

The total number of data points $n=f_1 + f_2+f_3+f_4=1 + 4+6 + 4=15$.

Step6: Calculate relative frequencies

The relative frequency of the class 2 - 7 is $rf_1=\frac{f_1}{n}=\frac{1}{15}\approx0.07$.
The relative frequency of the class 8 - 13 is $rf_2=\frac{f_2}{n}=\frac{4}{15}\approx0.27$.
The relative frequency of the class 14 - 19 is $rf_3=\frac{f_3}{n}=\frac{6}{15}=0.40$.
The relative frequency of the class 20 - 25 is $rf_4=\frac{f_4}{n}=\frac{4}{15}\approx0.27$.

Answer:

Number of hours	Relative frequency
8 to 13	0.27
14 to 19	0.40
20 to 25	0.27