Question

If all the observations 3, 7, 9, 18, 21, 32 arc multiplied by 3, then the new mean is ___ (a) 15
(b) 90
(c) 45
(d) 60

Answer 1

old mean =( 3+7+9+18+21+32)/6

= 90/6

= 15

new mean = 15 × 3

= 45

your ans is 45 option C

Answer 2

Answer:

Option (b) is correct

Step-by-step explanation:

Given observations :

3,7,9,18,21,32

$Mean = \frac{Sum\:of\: observations }{Number\:of\: observations}$

$=\frac{3+7+9+18+21+32}{6}\\=\frac{90}{6}\\=15$

According to the problem given,

if each observation is multiplied by 3 ,

$New \: mean = 3\times Old \mean$

$=3\times 15\\=45$

•••♪