Question

Ms. Rivera created two dot plots to compare the results of her recent science quiz for 1st period students compared to 7th period students. The dot plots are displayed to the right. Use this information to answer the questions below.

Answer 1

The dot plots is an illustration of charts and graphs

The average score of period 7 is greater than the average score of period 1

How to determine the period with the higher average?

From the dot plots in the complete question, we have the following frequency tables

Period 1                                                          Period 7

Score     Students                                          Score     Students

55           1                                                         65           1

70           1                                                         75           3

75           6                                                         80         5

80           6                                                         85         6

85           2                                                         90         3

90           3                                                         95        2

95           1                                                                

The average is calculated using:

$\bar x = \frac{\sum fx}{\sum f}$

For period 1, we have:

$\bar x_1 = \frac{55 * 1 + 70 * 1 + 75 * 6 + 80 * 6 + 85 * 2 + 90 * 3 + 95 * 1}{1 + 1 + 6 + 6 + 2 + 3 + 1}$

Evaluate the sum

$\bar x_1 = \frac{1590}{20}$

Evaluate the quotient

$\bar x_1 = 79.5$

For period 7, we have:

$\bar x_7 = \frac{65 * 1 + 75 * 3 + 80 * 5 + 85 * 6 + 90 * 3 + 95 * 2}{1 + 3 + 5 + 6 + 3 + 2}$

Evaluate the sum

$\bar x_7 = \frac{1660}{20}$

Evaluate the quotient

$\bar x_7 = 83$

By comparison, 83 is greater than 79.5

Hence, the average score of period 7 is greater than the average score of period 1

Read more about dot plots at:

https://brainly.com/question/12276901