Standard 2 Warmup

If quartiles Q1=50 and Q3=70, which of the following is true?

• The median is 60.

• The mean is between 50 and 70.

• The standard deviation is at most 20.

• The range must be greater than 20.

• None may be true.

Which of the following statements is incorrect?

• Both dotplots and stemplots can show symmetry, gaps, clusters, and outliers.

• Sets with different distribution shapes can have identical boxplots.

• Boxplots, dotplots, stemplots and histograms can show all skewness.

• In histograms, relative areas correspond to relative frequencies.

• In histograms, frequencies can be determined from relative heights.

A data set includes two outliers, one at each end. If both outliers are removed, which of the following is a possible result?

• Both the mean and standard deviation remain unchanged.

• Both the median and standard deviation remain unchanged.

• Both the standard deviation and variance remain unchanged.

• Both the mean and median remained unchanged.

• Both the mean and standard deviation increase.

• A

• B

• C

• D

• E

These dotplots for randomly selected mail and female students at a particular high school show the number of times per week they eat fast food restaurants. Which of the following is a true statement?

• One distribution is roughly symmetric; the other is skewed left.

• The difference in their means is less than the difference in their medians.

• The ranges are both 7-0=7

• The standard deviations are the same.

• Combining the mail and female times into one set of student times will increase the range to the sum of the individual ranges.