PLEASE ANSWER THIS Q

Dear student,
Answer:

From the question we get

$\frac{Sum of 11 observations}{11}$ =  35  , So

Sum of 11 observation =  35 $\times$ 11  =  385

Now each observation is then changed to 15 less than 4 times the original observation.

So , we have

Sum of new 11 observation  =  [ 4 ( 1^st observation ) - 15 ] + [ 4 ( 2^nd observation ) - 15 ] + [ 4 ( 3^rd observation ) - 15 ] + ... + [ 4 ( 11^th observation ) - 15 ]

So,
Sum of new 11 observation  =  4 ( 1^st observation + 2^nd observation + 3^rd observation + ...+ 11^th observation  ) -  15 $\times$ 11

Sum of new 11 observation  =  4 (Sum of 11 observation  ) - 165

Sum of new 11 observation  =  4 ( 385  ) - 165

Sum of new 11 observation  =  1540 - 165

Sum of new 11 observation  =  1375

So

New Mean = $\frac{1375}{11}$ =  125  ( Ans )
Regards