The video tutorial explains how to interpret and use histograms to calculate frequencies and estimate the lower quartile of a dataset. It covers the relationship between the area of histogram bars and frequency, demonstrates filling a frequency table, and guides on finding the lower quartile using the total number of students.

What does the vertical axis represent in the histogram discussed?

• Number of students

• Frequency density

• Class interval

• Time taken in minutes

How is the frequency of an interval represented in a histogram?

• By the area of the bar

• By the width of the bar

• By the color of the bar

• By the height of the bar

What is the width of the second column in the histogram?

• 20

• 15

• 10

• 5

What is the height of the third column in the histogram?

• 0.2

• 0.6

• 0.4

• 1.0

How many students were surveyed according to the frequency table?

• 17

• 25

• 30

• 23

Which formula is used to find the lower quartile in this context?

• N / 2

• N + 1 / 4

• N / 4

• N + 1 / 2

What is the estimated lower quartile of the times taken to finish the puzzle?

• 5 minutes

• 10 minutes

• 15 minutes

• 20 minutes