Question

the mean of 53 observations is 36.Out of these observations ,the mean of first 27 observations is 32.and that of the last 27 observations is 40.find the 27th observation
a)23 b) 36 c)38 d)40
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Answer 1

Answer:

the correct option is letter b

Step-by-step explanation:

Mean of 25 observations =36

Sum of 25 observations = 36×25=900

Mean of first 13 observations= 32

Sum of first 13 observations = 32×13=416

Mean of Last 13 observation=40

Sum of Last 13 observations = 40×13 = 520

Sum of first13 observation+ Sum of last13 obs − 13th observation= Total sum of 25 observations

416+520−13th observation=900

13 th observation =36

Answer 2

Answer:

36

Step-by-step explanation:

Mean of 25 observations =36

Sum of 25 observations = 36×25=900

Mean of first 13 observations= 32

Sum of first 13 observations = 32×13=416

Mean of Last 13 observation=40

Sum of Last 13 observations = 40×13 = 520

Sum of first13 observation+ Sum of last13 obs − 13th observation= Total sum of 25  observations

416+520−13th observation=900

13 th observation  =36