The commission earned, in thousands of rands, by the salesmen of a particular company in a certain month is shown in the table below - NSC Mathematics - Question 2 - 2017 - Paper 2
Question 2
The commission earned, in thousands of rands, by the salesmen of a particular company in a certain month is shown in the table below.
COMMISSION EARNED (IN THOUSAND... show full transcript
Worked Solution & Example Answer:The commission earned, in thousands of rands, by the salesmen of a particular company in a certain month is shown in the table below - NSC Mathematics - Question 2 - 2017 - Paper 2
Step 1
2.1 Write down the modal class of the data.
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Answer
The modal class is the class with the highest frequency. From the table, the class '80 < x ≤ 100' has the highest frequency of 10. Thus, the modal class is 80 < x ≤ 100.
Step 2
2.2 Complete the cumulative frequency column in the table given in the ANSWER BOOK.
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Answer
To complete the cumulative frequency, we add the frequency of each class to the cumulative frequency of the previous class:
For 20 < x ≤ 40: Cumulative Frequency = 7
For 40 < x ≤ 60: Cumulative Frequency = 7 + 6 = 13
For 60 < x ≤ 80: Cumulative Frequency = 13 + 8 = 21
For 80 < x ≤ 100: Cumulative Frequency = 21 + 10 = 31
For 100 < x ≤ 120: Cumulative Frequency = 31 + 4 = 35
The completed cumulative frequency table is:
COMMISSION EARNED FREQUENCY CUMULATIVE FREQUENCY
20 < x ≤ 40 7 7
40 < x ≤ 60 6 13
60 < x ≤ 80 8 21
80 < x ≤ 100 10 31
100 < x ≤ 120 4 35
Step 3
2.3 Draw an ogive (cumulative frequency curve) to represent the data on the grid provided in the ANSWER BOOK.
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Answer
To draw the ogive, plot the cumulative frequencies against the upper class boundaries:
(40, 7)
(60, 13)
(80, 21)
(100, 31)
(120, 35)
Connect these points with a smooth curve to create the ogive.
Step 4
2.4 A salesman receives a bonus if his commission is more than R90 000 for the month. Calculate how many of the salesmen received bonuses for this month.
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Answer
A commission of more than R90 000 corresponds to more than 90 in thousands of rands. From the cumulative frequency, those in the class '100 < x ≤ 120' (with a frequency of 4) received bonuses. Thus, 4 salesmen received bonuses.
Step 5
2.5 Determine the approximate mean commission earned by the salesmen in this month correct to the nearest thousand rand.
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Answer
To find the approximate mean, we use the midpoint of each class:
Midpoint for 20 < x ≤ 40 = 30
Midpoint for 40 < x ≤ 60 = 50
Midpoint for 60 < x ≤ 80 = 70
Midpoint for 80 < x ≤ 100 = 90
Midpoint for 100 < x ≤ 120 = 110
Then we calculate:
Mean = ( \frac{(30 \times 7) + (50 \times 6) + (70 \times 8) + (90 \times 10) + (110 \times 4)}{35} )
Mean = ( \frac{(210 + 300 + 560 + 900 + 440)}{35} = \frac{2410}{35} \approx 68.86 )
Thus, the approximate mean commission earned is R69 000 when rounded to the nearest thousand rand.