1st Nine Week Test Review

Isabella collected data on the class counts at her school and recorded the grade level of each student. She then made a bar graph of her data. Which statement is true based on Isabella’s bar graph?

• The number of Seniors is three times the number of Juniors.

• The number of Freshman is more than two times the number of Sophomores.

• The number of Sophomores is greater than all the other classes combined.

• The number of Freshmen is less than the number of Sophomores and Juniors combined.

Which type of graph would be most appropriate to display data about students’ favorite type of ice cream?

• Stem-and-leaf plot

• Histogram

• Bar Graph

• Dot Plot

Determine whether the statement is true or false. If it is false, rewrite it as a true statement. A population is the collection of some outcomes, responses, measurements, or counts that are of interest.

• False. A sample is the collection of all outcomes, responses, measurements, or counts that are of interest.

• True.

• False. A population is the collection of all outcomes, responses, measurements, or counts that are of interest.

The below stem-and-leaf plot displays the Nest Egg Index - a measure of savings and investments in all 50 states. Which of the following statements about the display is correct?

• The distribution of the Nest Egg Index for the Northeast and Midwest is more skewed right than the South and West.

• Both distributions are approximately symmetrical.

• Both distributions have outliers on the low end.

• The distribution of the Nest Egg Index for the Northeast and Midwest is more skewed left than the South and West.

Consider these six data values: 2, 4, 5, 11, 13, 15. Now look at the data set: 82, 84, 85, 91, 93, 95. Without doing any calculations, explain why the standard deviation will be the same even though the mean is obviously different.

• The standard deviation will remain the same because the values in the second data set are the same distances away from their mean as the values in the first set.

• The standard deviation will remain the same because the distribution of the second set of values is symmetrical.

• The standard deviation will remain the same because adjusting values within a data set only affects the center of that data set, not its spread.

• The standard deviation will remain the same because adjusting values within a data set only affects the shape of that data set, not its spread.

Using the stem and leaf plot below, without doing any calculations, which must be larger – the median or the mean? Explain how you know.

• The median will be larger than the mean because the distribution is skewed to the right.

• The mean will be larger than the median because the distribution is skewed to the right.

• The mean and median are approximately equal because the distribution is symmetric.

• The mean will be lower than the median because the distribution is skewed to the left.

You are allowed to choose four numbers from 1 to 10 (inclusive, without repeats). Which of the following is false?

• The numbers 4, 5, 6, 7 have the smallest possible standard deviation.

• The numbers 1, 2, 3, 4 have the smallest possible standard deviation.

• The numbers 1, 5, 6, 10 have the largest possible standard deviation.

• The numbers 1, 2, 9, 10 have the largest possible standard deviation.

• The numbers 7, 8, 9, 10 have the smallest possible standard deviation.

Which of the following is not a measure of the center of a data set?

• lower quartile

• mode

• median

• mean

• none of these are measures of center

Which of the following is not a measure of the variability in a data set?

• interquartile range

• variance

• upper quartile

• standard deviation

• range

An observation is an outlier if it is more than:

• 1.5*IQR below Q1 and 1.5*IQR above Q3

• 2*IQR below Q1 and 2*IQR above Q3

• 2.5*IQR below Q1 and 2.5*IQR above Q3

• 3*IQR below Q1 and 3*IQR above Q3