Question

Chapter 140 Statistics
Multiple Choice Questions
(1 mark each
1. The mean of five numbers is 10. If each number is decreased by 3. mean of the new
number is
(a) 13
(b) 10
(c) 7
d) None of these​

Answer 1

Answer:

$Mean = \frac{Sum}{No \: \: of \: \: Terms} \\ 10 = \frac{Sum}{5} \\ 10 \times 5 = Sum \\ \boxed{ \bf{ \underline{ \underline{50}} = Sum}} \\ \\ If \: \: each \: \: number \: \: is \: \: decreased \: \: by \: \: 3 \\ That \: \: is \: , \\ 50 - (3 \times 5) \\ = 50 - 15 \\ \boxed{ \bf{={ \underline{ \underline {35}}}}} \\ \\ Mean \: \: of \: \: New \: \: Numbers \: \: is: \\ Mean = \frac{Sum}{No \: \: of \: \: Terms} \\ = \frac{35}{5} \\ \boxed{ \bf{={ \underline{ \underline {7}}}}}$