2026 EVG P1 Q14

Secondary 4

4 marks

The table below shows the mass of 500 packets of 1 kg chocolate packed by machine A.

Mass (x grams)	\(980<x\leq990\)	\(990<x\leq1000\)	\(1000<x\leq1010\)	\(1010<x\leq1020\)
Frequency	74	178	182	66

Calculate an estimate of the mean mass. Leave your answer to 1 decimal place.[1]
Calculate an estimate of the standard deviation.[1]
The mean and standard deviation of mass of chocolate packed by machine B is given below.
Measure Value
Mean (grams) 1000.2
Standard deviation (grams) 12.5
If you are the owner of the chocolate distribution business, which machine will you buy? Explain your reason.[2]

Measure	Value
Mean (grams)	1000.2
Standard deviation (grams)	12.5

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Answer:(a) 999.8 g. (b) 9.00 g. (c) A: smaller spread with a mean equally close to 1000 g.

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