A secondary school conducted a survey on the amount of pocket money male and female students received each month. The cumulative frequency curves below represent the distributions of the amounts received by each group.
Use the curve to estimate
the median monthly pocket money the male students received,[1]
the interquartile range of the monthly pocket money the male students received.[2]
Find the number of students who received more than $300 of pocket money each month.[2]
Amy said, “In this survey, the percentage of male students who received above $300 of pocket money each month is higher than the percentage of female students who received above $300 of pocket money each month.” Do you agree with this statement? Justify your answer.[2]
The school realised that there is a mistake in the data. One of the male student’s monthly pocket money should be $300 instead of $250. How does this affect the accuracy of the interquartile range of the male students’ monthly pocket money?[1]