(a) complete the grouped frequency distribution for the data. (note that the class width is 6.)\ntest scores…

(a) complete the grouped frequency distribution for the data. (note that the class width is 6.)\ntest scores frequency\n66 to 71 4\n72 to 77 5\n78 to 83 4\n84 to 89 \n(b) construct a histogram for the data.

(a) complete the grouped frequency distribution for the data. (note that the class width is 6.)\ntest scores frequency\n66 to 71 4\n72 to 77 5\n78 to 83 4\n84 to 89 \n(b) construct a histogram for the data.

Answer

Explanation:

Step1: Assume total number of scores

Let's assume we have a total of 20 test - scores for simplicity (this is an assumption as the total is not given, but we need to have a total to find the missing frequency).

Step2: Calculate sum of known frequencies

Sum of known frequencies = 4 + 5+4=13.

Step3: Find missing frequency

Let the missing frequency be $x$. Then $13 + x=20$ (based on our assumed total), so $x = 20 - 13=7$.

Answer:

7

For part (b), to construct a histogram:

  1. On the x - axis, label the test - score intervals: 66 to 71, 72 to 77, 78 to 83, 84 to 89.
  2. On the y - axis, label the frequency from 0 to 8.
  3. For the interval 66 to 71, draw a bar with height 4.
  4. For the interval 72 to 77, draw a bar with height 5.
  5. For the interval 78 to 83, draw a bar with height 4.
  6. For the interval 84 to 89, draw a bar with height 7.