Question

A frequency table of grades has five classes (A, B, C, D,F) with frequencies of 4, 10, 17, 6, and respectively. Using percentages, what are the relativefrequencies of the five classes?Complete the table.Grade Frequency Relative frequencyA4%B 10%%D 6%2%(Round to two decimal places as needed.)с17F

Answer 1

We have the frequencies for each of the grades. We can estimate the number of students graded by adding all those frequencies. Let's call N the total number of grades:

$\begin{gathered} N=4+10+17+6+2 \\ N=39 \end{gathered}$

We have then a total number of grades of 39.

The corresponding relative frequency for a grade is the ratio of the frequency to the total number of "samples", 39 in this case.

Then, for grade A, the relative frequency (RF) will be:

$RF_A=\frac{4}{39}\approx0.10256\approx10.26\text{ \%}$

This will be the fraction of the total grades that are A. Represented as a percentage will be 10.26%, rounded to two decimal places.

Now, to complete the table we do the same for the other frequencies:

For grade B:

$RF_B=\frac{10}{39}\approx0.2564\approx25.64\text{ \%}$

For grade C:

$RF_C=\frac{17}{39}\approx0.4359\approx43.59\text{ \%}$

For grade D:

$RF_D=\frac{6}{39}\approx0.1538\approx15.38\text{ \%}$

For grade F:

$RF_D=\frac{2}{39}\approx0.0513\approx5.13\text{ \%}$