MathCumulative Frequency
posted by Nneka .
The score obtained by 100 applicants on an aptitude tests for selection into a program are shown in the frequency table.
Score Frequency Cumulative Freq
09 8 8
1019 13 8+13=21
2029 17 21+17=38
3039 20 38+20=58
4049 19 58+19=77
5059 14 77+14=91
6069 6 91+6=97
7079 3 67+3=100
(a)Draw a cumulative frequency curve using 2cm to represent each class interval and 2cm to represent 10 applicants.
(b)Using your curve,answer the following:
(i)A score of 45 was considered as acceptable for the program.Estimate the number of applicants who qualified for entry.
(ii)Assuming there were places for only 15 applicants,estimate the lowest score that would be used to select them.
(iii)Calculate the probability that an applicant chosen at random obtained a score of at least 45.
Please help me. Thank you.

Well, I am not certain what you don't understand. You are given the data points. for instance, at 59, you have the point (59,91)
do all the points that way, then plot.