Tuesday, March 31, 2009

Question to Draw Box Plot for a Collection of Data

Topic : Box Plot

Question : In a survey of the cafeteria food at Metropiolis Middle School, 50 students were asked to rate how well they liked the lunches on a scale of 1 to 10, with 1 being the lowest rating and 10 being the highest rating. The box plot was made from the collected data.
What percent of the students in the sample rated the cafeteria food between 5.75 and 9


Solution :








First Quartile = Q1 = 5.75
That is 25% of students lie between 3 and 5.75
Second Quartile = Q2 = 6.5
That is 50% of students lie between 3 and 6.5
Third Quartile = Q3 = 8
That is 75% of the students lie between 3 and 8
100% of students lie between 3 and 9
So the % of students who lie between 5.75 and 9 = 100% - 25% = 75%
and Answer is 75%