Question

ns is taking a self - paced math class. his scores for each of the 13 quizzes during the academic year are shown below. complete the grouped relative frequency distribution for the data. (note that we are using a class width of 4.) write each relative frequency as a decimal rounded to the nearest hundredth, not as a percentage. quiz score: 83 80 74 76 74 88 82 89 85 79 75 90 81 quiz score: 72 to 75, 76 to 79, 80 to 83, 84 to 87, 88 to 91 relative frequency:

Explanation:

Step1: Count frequencies

For the class 72 - 75, the scores in this range are 74, 74, 75. So the frequency $f_1 = 3$.
For the class 76 - 79, the scores are 76, 79. So the frequency $f_2=2$.
For the class 80 - 83, the scores are 83, 80, 82, 81. So the frequency $f_3 = 4$.
For the class 84 - 87, there are no scores in this range. So the frequency $f_4=0$.
For the class 88 - 91, the scores are 88, 89, 90. So the frequency $f_5 = 3$.
The total number of data points $n=13$.

Step2: Calculate relative frequencies

The relative - frequency formula is $rf=\frac{f}{n}$.
For the class 72 - 75, $rf_1=\frac{3}{13}\approx0.23$.
For the class 76 - 79, $rf_2=\frac{2}{13}\approx0.15$.
For the class 80 - 83, $rf_3=\frac{4}{13}\approx0.31$.
For the class 84 - 87, $rf_4=\frac{0}{13}=0.00$.
For the class 88 - 91, $rf_5=\frac{3}{13}\approx0.23$.

Answer:

Quiz score	Relative frequency
76 to 79	0.15
80 to 83	0.31
84 to 87	0.00
88 to 91	0.23