Question 6(b)(ii)
Two students do an experiment to determine their power when running up a set of steps.
The diagram shows how they set up their experiment. Not all of the steps are shown in the diagram.

This is the students' method.
- student A stands with a stopwatch at the top of the steps
- student A starts timing on the stopwatch and shouts "go" at the same time
- student B begins to run up the steps when she hears student A shout
- student A stops timing when student B reaches the top of the steps
The students repeat their method two more times.
There are 24 steps in total and each step has a height of 19 cm .
The table shows the times recorded for student B.

Calculate the mean time from this data.
Give your answer to three significant figures.
