8/18/2019 Worksheet 3.2 Averages

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  Section 3.2: Right Down the Middle

When Are We Ever Going To Use This Stuff, Sixth Edition, Matovina & Yates

For #1-4, find the mean, median and mode of each data set. Round any decimal answers to the nearesttenth.

1.  {10, 33, 50, 50, 76, 81, 50, 11}

2.  {5, 5, 5, 5, 11, 12, 7, 15, 13}

3. 

{73, 25, 48, 99, 73, 71}

4.  {4, 16, 9, 4, 2, 4, 1, 4, 16, 9, 4, 2, 4, 1}

5.  The mean score on a set of 25 exams is 79.2. What is the sum of the 25 exam scores?

6.  A class of 22 students has taken an exam, and the mean of their scores is 76.5. One student takes theexam late, and scores 92. After including the new score, what is the mean score for all 23 exams?Round to the nearest hundredth.

8/18/2019 Worksheet 3.2 Averages

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  Section 3.2: Right Down the Middle

When Are We Ever Going To Use This Stuff, Sixth Edition, Matovina & Yates

7. 

After three exams, Jenny has a mean score of 74. With only one exam remaining in the class, what isthe minimum score she will need on that exam to have an overall mean of 80?

8.  The following table gives number of classes taken by 20 students thisterm. Find the mean, median, and mode number of classes taken.

9. 

 Joe earned a B- in his 5-cr math class, a B in his 4-cr English class, an F in his 3-cr chemistry class,and an A in his 2-cr PE class. What is his GPA for the term?

10. 

Ken earned a A- in his 5-cr English class, a B in a 4-cr physics class, a B+ in a 3-cr Spanish class, andan A in his 3-cr sociology class. What is her GPA for the term?

Classes Students

1 42 23 54 65 3

8/18/2019 Worksheet 3.2 Averages

3/3

  Section 3.2: Right Down the Middle

When Are We Ever Going To Use This Stuff, Sixth Edition, Matovina & Yates

Solutions:

1.  mean = 361/8 = 45.1, median = (50+50)/2 = 50, mode = 50

2. 

mean = 78/9 = 8.7, median = 7, mode = 5

3. 

mean = 389/6 = 64.8median = (71+73)/2 = 72mode = 73

4.  mean = 80/14 = 5.7median = (4+4)/2 = 4mode = 4

5. 

mean = sum/25! 25(mean) = sum! sum = 25(79.2) = 1980

6.  For the first 22 scores, sum = 22(mean) = 22(76.5) = 1683.Add in the 92 to get the new sum of 1775.

The new mean is 1775/23 = 77.17

7.  She has 3(74) = 222 points, and needs 4(80) = 320 points for a mean of 80.Thus, she needs at least a 98.

8. 

mean = [1(4)+2(2)+3(5)+4(6)+5(3)]/20 = 3.1median of 20 values is the mean of the values in the 10th and 11th places. (3+3)/2 = 3mode = 4

9. 

GPA = [2.7(5)+3.0(4)+0.0(3)+4.0(2)]/14 = 33.5/14 = 2.39

10. 

GPA = [3.7(5)+3.0(4)+3.3(3)+4.0(3)]/15 = 52.4/15 = 3.49