(a(i))[1]
Use the diagram to estimate the median.
(a(ii))[2]
A total of $60\%$ of the students passed the test. Use the diagram to determine how many marks were needed to pass.
(a(iii))[2]
Using the information shown on the diagram, complete the frequency table.
(b)[5]
The times taken by the 80 students to finish a Science test are displayed in the frequency table. The estimated mean time to complete the test is $67.625$ minutes. This is found by using the mid-interval value as an estimate of the time in each class interval. Calculate the value of $p$ and the value of $q$.