Data Collection and Measures of Center and Spread

• 136
• 150
• 156
• 153

• Kim's scores are more consistent.
• Caleb's scores are more consistent.
• Both scores have the same consistency!
• Not enough information is provided.

The number of text messages that Isaac received each day for a week is shown: 47, 49, 54, 50, 48, 47, 55
What is the mean and median

• Mean=49
  Median=54

• Mean=49 
  Median=50

• Mean=50 
  Median=54

• Mean=50
  Median=49

The numbers of runs scored by a softball team in 20 games are given.
 3, 4, 8, 12, 7, 5, 4, 12, 3, 9, 11, 4, 14, 8, 2, 10, 3, 10, 9, 7
What is the median of this data.

• Median = 7.5

• Median = 7

• Median = 8

• Median = 12

Which summary statistic should be used to compare the two data sets and why?

• The median and the interquartile range because they are normally distributed.

• The median and the interquartile range because they are skewed.

• The mean and the standard deviation because they are normally distributed.

• The mean and the standard deviation because they are skewed.

A class scored 83,83,87,87,88,88,91,94,95,96,98,100,100 on a test, but then a student scored a 28.

The mean will ​ (a)  

The median will ​ (b)  

The ​ (c)   is the best measure of center for this data.

• decrease

• increase

• stay the same

• go up

• go down

• median

• mean

The numbers of runs scored by a softball team in 20 games are given.
 3, 4, 8, 12, 7, 5, 4, 12, 3, 9, 11, 4, 14, 8, 2, 10, 3, 10, 9, 7
What is the Interquartile Range.

• IQR = 6

• IQR = 10

• IQR = 7.5

• IQR = 12

Quartiles are values that divide a data set into four equal parts.

• True

• False

The first quartile (Q 1) is the median of the lower half of the set.
The second quartile (Q 2) is the median of the whole set .
The third quartile (Q 3) is the median of the upper half of the set.

• All three statements are true.

• Only the 1st statement is true.

• Only the 2nd and the 3rd statements are true.

• Only the 3rd statement is true.

The interquartile range (IQR) of a data set is the difference between the third and first quartiles. It represents the range of the middle half of the data.

• True

• False