Question

Monthly Expenses (S$) Frequency
0 and less than 150 5
150 and less than 300 8
300 and less than 450 15
450 and less than 600 9
600 and less than 750 17
750 and less than 900 6
Total 60

If 80% of the monthly expenses is below $600, then it indicates that the XYZ has not been overspending. From the above grouped data, would you say that XYZ has been overspending? show your calculation.

Answer 1

$$Monthly \ Expenses \ (S \$) \ \ \ \ Frequency$$ $$\ \ 0\leq S<150 \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 5$$ $$150\leq S<300 \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 8$$ $$300\leq S<450 \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 15$$ $$450\leq S<600 \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 9$$ $$600\leq S<750 \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 17$$ $$750\leq S<900 \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 6$$

Total 60 

$S<600: \ 5+8+15+9=37$

$80 \% \ of \ 60=48>37$

We would say that XYZ has been overspending.