Question

Urgent help please

Answer 1

Mean is the arithmatic average of a given data set. So,

$Mean= \frac{Sum of the data}{Number of the data}$

There are seven data in the data set.

According to the given problem,

$\frac{18+p+13+q+15+r+7 }{7} =11$

$\frac{53+p+q+r }{7} =11$ Combine the like terms of the numerator.

$\frac{53+p+q+r }{7}*7 =11 *7$ Multiplying 7 to each sides of equation.

53 + p + q + r = 77

53 + p + q + r - 53 = 77 - 53 Subtract 53 from each sides.

p + q + r = 24

Next step is to divide each sides by 3 so that we can write this in form of mean of p, q and r. Therefore,

$\frac{p + q + r}{3} =\frac{24}{3}$

So, mean of p, q and r = 8.

I hope this helps you!.