Question 132 of 208EasyMCQ
If the sum of the deviations of 50 observations from 30 is 50, then the mean of these observations is:
Solutions · 1
Official solution
\[\sum\limits_{i = 1}^{50} {\left( {{x_i} - 30} \right) = 50} \]
\[\sum {{x_i}} = 50 \times 30 = 50\]
\[\sum {{x_i}} = 50 + 50 + 30\]
Mean \[ = \overline x = {{\sum {{x_i}} } \over n} = {{50 \times 30 + 50} \over {50}}\]
=30+1=31 Answer the question to unlock