Question

ms. powell gave her students a biology test last week. here are the test scores for each of the eighteen students. test scores: 85 77 76 78 78 72 84 80 70 72 81 82 79 79 70 66 78 78 (a) complete the grouped frequency - distribution for the data. (note that the class width is 6.) test scores frequency 65.5 - 71.5 71.5 - 77.5 77.5 - 83.5 83.5 - 89.5 (b) construct a histogram for the data. frequency 10 9 8 7 6 5 4 3

Explanation:

Step1: Count scores in 65.5 - 71.5

The scores in the range 65.5 - 71.5 are 70, 70, 66. So the frequency is 3.

Step2: Count scores in 71.5 - 77.5

The scores in the range 71.5 - 77.5 are 77, 72, 72. So the frequency is 3.

Step3: Count scores in 77.5 - 83.5

The scores in the range 77.5 - 83.5 are 78, 78, 78, 78, 80, 81, 82, 79, 79. So the frequency is 9.

Step4: Count scores in 83.5 - 89.5

The scores in the range 83.5 - 89.5 are 85, 84. So the frequency is 2.

Answer:

Test scores	Frequency
71.5 - 77.5	3
77.5 - 83.5	9
83.5 - 89.5	2

(Note: Constructing the histogram would involve drawing bars with the class - intervals on the x - axis and the frequencies on the y - axis, with the height of each bar corresponding to the frequency of the respective class - interval. But the above is just the completed frequency distribution table as asked in part (a).)