Question

The given data shows the weights (in kg) of students for a class of 8:

45, 25, 35, 20, 30, 40, 50, $x$.

One of the values is missing. It is known that the average weight of class is 35. What is the value of $x$?

• A.
  40
• B.
  35
• C.
  30
• D.
  25

Answer 1

The correct option is B

35
We know,
$Average=\frac{Sumofallobservations}{Totalnumberofobservations}$
$\Rightarrow$ $Average=\frac{45+25+35+20+30+40+50+x}{8}$

We know, Average = 35

$\Rightarrow$ $35=\frac{45+25+35+20+30+40+50+x}{8}$

$\Rightarrow$ $280=245+x$

$\Rightarrow$ $x=35kg$