Understanding Quartiles and Box Plots

The video tutorial explains how to create a box plot by identifying five key statistical values: minimum, maximum, median, first quartile (Q1), and third quartile (Q3). The instructor guides through finding these values from a data set, which is conveniently ordered. The minimum and maximum are the smallest and largest values, respectively. The median is the middle value, while Q1 and Q3 are the medians of the lower and upper halves of the data. Finally, the video demonstrates plotting these values to form a box plot, connecting Q1 to Q3 with a box and extending whiskers to the minimum and maximum.

What are the five key statistical values needed to create a box plot?

• Sum, product, difference, quotient, remainder

• Mean, median, mode, range, interquartile range

• Mean, mode, range, variance, standard deviation

• Minimum, maximum, median, first quartile, third quartile

How do you determine the minimum value in a data set?

• By finding the most frequently occurring number

• By calculating the difference between the largest and smallest values

• By identifying the smallest number in the data set

• By finding the average of all values

What is the maximum value in a data set?

• The most frequently occurring number

• The largest number in the data set

• The smallest number in the data set

• The average of all values

How is the median of a data set determined?

• By finding the average of all values

• By calculating the difference between the largest and smallest values

• By identifying the middle value in the ordered data set

• By finding the most frequently occurring number

What is the median value of the given data set?

• 130

• 142.5

• 139

• 150

How do you calculate the first quartile (Q1) of a data set?

• By finding the average of all values

• By identifying the middle value of the lower half of the data set

• By calculating the difference between the largest and smallest values

• By finding the most frequently occurring number

What is the value of the first quartile (Q1) in the data set?

• 150

• 139

• 132.5

• 130

How is the third quartile (Q3) of a data set determined?

• By finding the most frequently occurring number

• By calculating the difference between the largest and smallest values

• By identifying the middle value of the upper half of the data set

• By finding the average of all values

What is the value of the third quartile (Q3) in the data set?

• 150

• 142.5

• 132.5

• 130

What is the final step in creating a box plot?

• Drawing a line for the median

• Calculating the mean of the data set

• Connecting quartile 1 to quartile 3 and adding whiskers to the minimum and maximum

• Finding the mode of the data set