Help 1,2 ​

1    

92    97   53  90   95    98

Mean = Sum of the Values  / Number of Values  = 

[ 92 + 97 + 53 + 90 + 95    + 98  ]  /   6    =   87. 5

Variance  =  

(92 - 87. 5)   =  4.5    ⇒ 4.5^2  ⇒  20.25

(97 - 87.5)  =  9.5 ⇒ 9.5^2  =  90.25

(53 - 87.5)  = -34.5  ⇒ (-34.5)^2   = 1190.25

(90 - 87. 5) = 2.5 ⇒ 2.5^2  = 6.25 

(95 - 87.5) = 7.5 ⇒ 7.5^2 ⇒ 56.25

(98 - 87.5) = 10.5 ⇒ 10.5^2 ⇒ 110.25

Add the values in the last column  =  1473.5

Take this value and divide it by the number of data values  = 6

1473.5 / 6   =   245.58

The standard deviation is the square root of this  = 15.7

Second answer 

2

Mean   =  [  53 + 51  + 48 + 49 + 37 ]  / 5    = 47.6

Variance  =  [29.2 + 11.6 + 0.2 + 2 + 112.4 ]  / 5  = 31.1

SD =  sqrt (31.1)   =  5.6

First answer