Statistics - Percentiles - Quartiles - Box - Whisker plots

The 25th percentile does correspond to

• the upper quartile

• the median

• the lower quartile

the 75th percentile does correspond to

• the upper quartile

• the median

• the lower quartile

The 50th percentile does correspond to

• the upper quartile

• the median

• the lower quartile

 $The\ upper\ quartile\ -The\ lower\ quartile\ =$  

• The median

• A measure of the spread of the 50% of the data

• The interquartile

A measure of the spread of the central 50% of the data is given by

• The median

• The IQR ( interquartile)

• The range

The upper quartile within a set of ordered data is the

This data show the length of time, in minutes, it took 11 students to complete an essay;

15, 18, 19, 21, 22, 25, 26, 26, 28, 30, 31

The lower quartile, median and upper quartile are respectively

• 15 - 25 - 31

• 19 - 25 - 28

• 21 - 25 - 26

The box plots above shows information about the times taken by 40 girls to complete the same puzzle. The minimum and maximum values are

• 15 and 46

• 23 and 34

• 0 and 60

The box plots above shows information about the times taken by 40 girls to complete the same puzzle. The interquartile and the median are

•  $IQR=\ 31$  
  

   $Median=30$  
  

•  $IQR=\ 9$  
   $Median\ =\ 30$  
  

•  $IQR\ =\ 11$  
   $Median=30$  
  

The box plots above shows information about the times taken by 40 girls to complete the same puzzle. Thick the right statement(s)

• 50% of the girls completed the puzzle in less than 30 seconds

• 25% of the girls completed the puzzle in more than 23 seconds

• 25% of the girls completed the puzzle in more than 34 seconds

• 75% of the girls completed the puzzle in less than 34 seconds