The following table shows the marks obtained by two students,Ravi and Hashina,in $10$ tests (out of $100$ marks each).

Student	Marks
Ravi	$25, 50, 45, 30, 70, 42, 36, 48, 35, 60$
Hashina	$10, 70, 50, 20, 95, 55, 42, 60, 48, 80$

Who is more intelligent and who is more consistent?

(N/A) To determine who is more intelligent,we compare their mean marks $(\bar{x})$. To determine who is more consistent,we compare their coefficients of variation $(CV)$.
For Ravi:
Mean $\bar{x}_R = \frac{25+50+45+30+70+42+36+48+35+60}{10} = \frac{441}{10} = 44.1$
Variance $\sigma_R^2 = \frac{\sum x_i^2}{n} - (\bar{x}_R)^2 = \frac{25^2+50^2+45^2+30^2+70^2+42^2+36^2+48^2+35^2+60^2}{10} - (44.1)^2$
$= \frac{625+2500+2025+900+4900+1764+1296+2304+1225+3600}{10} - 1944.81$
$= 2113.9 - 1944.81 = 169.09$
Standard deviation $\sigma_R = \sqrt{169.09} \approx 13.00$
$CV_R = \frac{\sigma_R}{\bar{x}_R} \times 100 = \frac{13.00}{44.1} \times 100 \approx 29.48\%$
For Hashina:
Mean $\bar{x}_H = \frac{10+70+50+20+95+55+42+60+48+80}{10} = \frac{530}{10} = 53.0$
Variance $\sigma_H^2 = \frac{10^2+70^2+50^2+20^2+95^2+55^2+42^2+60^2+48^2+80^2}{10} - (53)^2$
$= \frac{100+4900+2500+400+9025+3025+1764+3600+2304+6400}{10} - 2809$
$= 3401.8 - 2809 = 592.8$
Standard deviation $\sigma_H = \sqrt{592.8} \approx 24.35$
$CV_H = \frac{\sigma_H}{\bar{x}_H} \times 100 = \frac{24.35}{53} \times 100 \approx 45.94\%$
Conclusion:
Since $\bar{x}_H > \bar{x}_R$,Hashina is more intelligent.
Since $CV_R < CV_H$,Ravi is more consistent.