Construct a frequency distribution and a relative frequency histogram for the data set using five classes. Which class has the greatest relative frequency and which has the least relative​ frequency?

Question

Ratings from 1​ (lowest) to 10​ (highest) from 36 taste testers

2 5 9 1 10 10 5 10 6

8 8 6 5 10 1 4 9 4

4 5 3 5 6 2 3 10 1

9 4 3 5 5 1 8 3 2

Find the class and frequencies :

1. ____ - ____ _____
2. ___ - ____ ______
3. ____ - ____ _____
4. ____ - ____ _____
5. ____ - _____ _____

Answer 1

Since there are 5 classes, we may use 20th percentiles to create bins/buckets for the data. First sort the values from smallest to largest. Then calculate the lower and upper values for the first 20th percentile (the upper value is a number for which approximately 20% of the sorted data is smaller or equal to, in this case 3), then continue doing this for the second 20th percentile (numbers between the 20% and 40% of sorted data) and continue the process. The percentiles can be calculated using Excel or any other statistical software. The buckets are obtained as [1-3], [3-4], [4-5], [5-9] and [9-10]. The first bucket [1-3] has highest frequency with 11 counts and second bucket [3-4] lowest frequency with 4 counts.