Question

Khilona earned scores of $97$, $73$ and $88$ respectively in her first three examinations. If she scored $80$ in the fourth examination, then her average score will be

• A. increased by $1$
• B. increased by $1.5$
• C. decreased by $1$
• D. decreased by $1.5$

Answer 1

The correct option is D decreased by $1.5$

When earned scores are $97,73,88$ then

Average $=\frac{97+73+88}{3}\Rightarrow 86.$

When $80$ is added in the score list then

Average $=\frac{97+73+88+80}{4}\Rightarrow 84.5$

Hence, the average is decreased by $\mathrm{1.5.}$