The table below shows the percentage mark distribution of a number of candidates in a physics examination. The table is in the attached image.

The completion of the table is :
Mark : 90-99
Frequency : 2

1. Make a cumulative frequency table and use it to draw the cumulative frequency curve.
II. from your graph estimate :
a. the Median Mark
b. the number of candidates that passed if the pass mark was 45% .
c. what is the probability that a person chosen at random from the candidates passed the examination.​