Statistics

The following is a cumulative frequency diagram for the time \(t\), in minutes, taken by \(80\) students to complete a task.

1. Write down the median.

   [1]

2. Find the interquartile range.

   [3]

3. Complete the frequency table below.

   [2]

   Time (minutes)	Number of students
   \(0 \leq t \leq 10\)	\(5\)
   \(10 \leq t \leq 20\)
   \(20 \leq t \leq 30\)	\(20\)
   \(30 \leq t \leq 40\)	\(24\)
   \(40 \leq t \leq 50\)
   \(50 \leq t \leq 60\)	\(6\)