The table below gives the frequency distribution of the marks obtained by some students in a scholarship examination.
Scores (x)
15
25
35
45
55
65
75
Freq (f)
1
4
12
24
18
8
3
(a) Calculate, correct to 3 significant figures, the mean mark.
(b) Find the : (i) mode ; (ii) range of the distribution.
Verified Correct Answer: .
Step-by-Step Mathematical Solution
(a)
x
f
fx
15
1
15
25
4
100
35
12
420
45
24
1080
55
18
990
65
8
520
75
3
225
70
3350
\(Mean = \frac{\sum fx}{\sum f} = \frac{3350}{70} = 47.8571\)
\(\approxeq 47.9\) (to 3 sig. figs)
(b)(i) Mode = 45 (score with the highest frequency)
(ii) Range = Highest mark - Lowest mark
= 75 - 15 = 60.
Source: Myschool Past Questions Archive (Record #54553)