9.2 Outliers and comparing dot plots

Paul earned the following scores on his quizzes: 78%, 92%, 84%, 85%, 75%, and 50%. Is his lowest score of 50% an outlier?

• Yes, because it is less than Q1 - 1.5 times the IQR of 10

• Yes, because it is less than Q3 - 1.5 the IQR of 10

• No, because it is more than Q1 + 1.5 times the IQR of 10

• No, because it is more than Q3 + 1.5 times the IQR of 10.

In Mrs. Middlebrook's check-in question today, on a scale of 1 - 10, the following student scores were recorded: 8,8,8,6,8,3,5,6,8,4,2. Is 2 an outlier?

• Yes, 2 is less than Q1 - 1.5 the IQR of 4

• Yes, 2 is less than Q1 - 2

• No, 2 is not less than Q1 - 1.5 times the IQR of 4

• No, 2 is more than Q3 + 1.5 times the IQR of 4.

A survey of students time spent playing video games per day resulted in the following data, in hours: 1, 2.5, 2.5, 3, 4, 4.5, 5, 6.5, 10 Is 1 hour an outlier?

• No, because it is not less than Q1 - 1.5 the IQR.

• Yes, because it is less than Q1 - 1.5 times the IQR.

• No, because it is more than Q3 + 1.5 times the IQR.

• Yes, because it is more than Q3 + 1.5 times the IQR.

Is 275 an outlier?

• Yes, because 275 is more than Q3 + 1.5 times the IQR of 15.

• Yes, because 275 is more than Q3 + 1.5 times the IQR of 20.

• No, because 275 is not more than Q3 + 1.5 times the IQR of 20.

• Yes, because 275 is at the top of the range.

The ages of the employees at which company tend to be lower than the other?

• Company A

• Company B

Tags

CCSS.7.SP.B.4

The ages of the employees at Company A tend to be closer together, than those at Company B.

• True

• False

Tags

CCSS.7.SP.B.4

The chart on the left shows the statistics on test scores in period 1 and period 5. Which is true?

• The average test score is higher for period 5, but the data is more spread out.

• The average test score is higher for period 1, but the data is more spread out.

• The average test score is higher for period 5, and the data is more consistent (closer to the mean) than period 1.

• The average test score is higher for period 1, and the data is more consistent (closer to the mean) than period 5.

Tags

CCSS.7.SP.B.4

The table on the right shows the statistics for the number of hours of homework per night during Term 1 and Term 2 for a group of students. What must be true?

• Term 1 students spent less time on homework than Term 2, but there was more variation in the number of hours spent on the homework.

• Term 2 students spent less time on homework than Term 1, but there was more variation in the number of hours spent on the homework.

• Term 1 students spent less time on homework than Term 2, but there was less variation in the number of hours spent on the homework.

• Term 2 students spent less time on homework than Term 1, but there was less variation in the number of hours spent on the homework.

Tags

CCSS.7.SP.B.4

Sylvia believes that the students in Term 2 had a higher average number of minutes of exercise than Term 1 because the IQR and Standard Deviation is higher for that group of students. Do you agree?

• Sylvia is correct. Since the standard deviation and IQR for Term 2 students is higher, this means that students spent more time exercising, on average, than Term 1.

• Sylvia is incorrect. The standard deviation and the IQR shows that there is greater variability in the amount of time exercising for Term 2 students compared to Term 1, but it does not tell us that the group spent more time exercising than Term 1.

Which of the following is a measure of spread, or variability?

(select all that apply)

• Interquartile range

• median

• mean

• standard deviation

Tags

CCSS.6.SP.A.3