It is given that the line plot below represents the number of letters written to overseas pen pals by the students at the Waverly middle school. Each x represents 10 students.
First of all count the number of x in the given line plot.
The total number of x in the line plot is 30. It means the total number of students is 30x = 30× x=300
From the figure, it is noticed that there are four x when the number of letters is 6 and three x where the number of letters is 20.
It means a total of 40 students wrote 6 letters and 30 students wrote 20 letters.
The number of students who wrote more than 6 but less than 20 letters is 300 - 40 - 30 = 230