Statistics

A test marked out of \(100\) is written by \(800\) students. The cumulative frequency graph for the marks is given below.

1. Write down the number of students who scored \(40\) marks or less on the test.

   [2]

2. The middle \(50\%\) of test results lie between marks \(a\) and \(b\), where \(a<b\).

   Find \(a\) and \(b\).

   [4]