The weights in pounds of four dogs are 165 393 396 and 337 W

The weights, in pounds, of four dogs are 16.5, 39.3, 39.6 and 33.7. What is the sample average? State your answer rounded to two decimal places.

The weights, in pounds, of three dogs are 12.5, 39.9, and 19.8. Calculate the unbiased estimate of the population variance. State your answer rounded to two decimal places.

Solution

A)

Xbar = Sum(x) / n = (16.5+39.3+39.6+33.7)/4 = 32.275 [ANSWER]

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b)

Getting the mean, X,          
          
X = Sum(x) / n          
Summing the items, Sum(x) =    72.2      
As n =    3      
Thus,          
X =    24.06666667      
          
Setting up tables,          
x   x - X   (x - X)^2  
12.5   -11.56666667   133.7877778  
39.9   15.83333333   250.6944444  
19.8   -4.266666667   18.20444444  
          
          
Thus, Sum(x - X)^2 =    402.6866667      
          
Thus, as           
          
s^2 = Sum(x - X)^2 / (n - 1)          
          
As n =    3      
          
s^2 =    201.3433333   [ANSWER, SAMPLE VARIANCE]