UNIT 2- MILESTONE 2 INTRODUCTIO TO
STATISTICS EXAM/ Q&A.
The midterm exam scores obtained by boys and girls in a class are listed in the
table below
What does the circled section represent?
Twelve boys scored 8 marks on the exam.
Two boys scored between 80 and 89 marks on the exam.
Eight boys scored over 10 marks on the exam.
Eight boys scored 12 marks on the exam. - Answer: If we recall that the stem and
leaf can give us the actual values in the data set, then the circle corresponds to 81
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, and 82. We can then note that there are two scores from boys between 80 and
89.
Sara wonders what percentage of her students answered at least half of the quiz
questions incorrectly.
The cumulative frequency of students who earned a score of 20 or lower on the
quiz is __________. - Answer: To get cumulative frequency of 20 or less, we
simply add up any bin that has the number 20 or less, such as the bin that shows
scores of 1-5, 6-10, 11-15, and 16-20.
The manager went over the sales of mobile phones at the store and found that
the mean sale was 45, with a standard deviation of 4. On a particular day, 52
mobile phones were sold.
What is the z-score of the sale of mobile phones on that day?
28
-28
1.75
-1.75 - Answer: Recall that the z-score can be calculated with the following
formula:
Z - SCORE = VALUE - MEAN / STANDARD DEVIATION
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STATISTICS EXAM/ Q&A.
The midterm exam scores obtained by boys and girls in a class are listed in the
table below
What does the circled section represent?
Twelve boys scored 8 marks on the exam.
Two boys scored between 80 and 89 marks on the exam.
Eight boys scored over 10 marks on the exam.
Eight boys scored 12 marks on the exam. - Answer: If we recall that the stem and
leaf can give us the actual values in the data set, then the circle corresponds to 81
Page 1 of 6
, and 82. We can then note that there are two scores from boys between 80 and
89.
Sara wonders what percentage of her students answered at least half of the quiz
questions incorrectly.
The cumulative frequency of students who earned a score of 20 or lower on the
quiz is __________. - Answer: To get cumulative frequency of 20 or less, we
simply add up any bin that has the number 20 or less, such as the bin that shows
scores of 1-5, 6-10, 11-15, and 16-20.
The manager went over the sales of mobile phones at the store and found that
the mean sale was 45, with a standard deviation of 4. On a particular day, 52
mobile phones were sold.
What is the z-score of the sale of mobile phones on that day?
28
-28
1.75
-1.75 - Answer: Recall that the z-score can be calculated with the following
formula:
Z - SCORE = VALUE - MEAN / STANDARD DEVIATION
Page 2 of 6
