### Common Errors in the recent Pop Quiz on Chapter 16 (Data Handling)

Here are questions that were not correctly answered by some of you...

Question 1

Let's figure out the number of SMSes and Phone calls respectively:
Number of SMSes = 11 + 10 + 9 + 13 + 14
= 57
Number of Phone calls = 4 + 15 + 6 + 14 + 12
= 51

Ratio of SMSes to Phone Calls will be = 57 : 51 {this can be further reduced}
= 19 : 17 [Ans]

Question 5

Given that number of cashiers is 10.
There are 2 groups of cashiers: Tidbit Cashiers and Ticket Cashiers.
Angle representing the cashiers = 360° - 170° - 70°
= 120°

120° represents 10 workers
So, 360° will represent all the workers.
Total number of workers = 10/120 x 360
= 30 workers [Ans]

Question 6

The year it experienced a sharp increase is Year 2008, and it's compared with Year 2007.

Since comparison makes reference to the previous reference point, the number in Year 2007 will serve as the base (which is 7,600).
The difference is 6,000.
Hence the percentage difference would be 6000/7600 x 100%
which gives 78.947368....% = 78.9% (3 S.F.)