Given, Population is 2 , 3 , 6 , 7 , 9 2,3,6,7,9 2 , 3 , 6 , 7 , 9
Sample size, n = 2 n=2 n = 2
The sampling distribution are as follows:-
(A). Mean of sampling distribution of means
=2.5 + 4 + 4.5 + 5.5 + 4.5 + 5 + 6 + 6.5 + 7.5 + 8 + 2 + 3 + 6 + 7 + 9 15 = 81 10 = 8.1 \dfrac{2.5+4+4.5+5.5+4.5+5+6+6.5+7.5+8+2+3+6+7+9}{15}=\dfrac{81}{10}=8.1 15 2.5 + 4 + 4.5 + 5.5 + 4.5 + 5 + 6 + 6.5 + 7.5 + 8 + 2 + 3 + 6 + 7 + 9 = 10 81 = 8.1
(B) Variance of sampling distribution of means
= ∑ ( X ˉ − X i ) 2 10 =\sum\dfrac{(\bar{X}-X_i)^2}{10} = ∑ 10 ( X ˉ − X i ) 2
= ( 6.2 ) 2 + ( 4.1 ) 2 + ( 3.6 ) 2 + ( 2.6 ) 2 + ( 3.6 ) 2 + ( 2.1 ) 2 15 + ( 1.6 ) 2 + ( 2.1 ) 2 + ( 1.1 ) 2 + ( 0.1 ) 2 + ( 6.1 ) 2 + ( 5.1 ) 2 + ( 2.1 ) 2 + ( 1.1 ) 2 + ( 0.9 ) 2 15 =\dfrac{(6.2)^2+(4.1)^2+(3.6)^2+(2.6)^2+(3.6)^2+(2.1)^2}{15}\\+\dfrac{(1.6)^2+(2.1)^2+(1.1)^2+(0.1)^2+(6.1)^2+(5.1)^2+(2.1)^2+(1.1)^2+(0.9)^2}{15} = 15 ( 6.2 ) 2 + ( 4.1 ) 2 + ( 3.6 ) 2 + ( 2.6 ) 2 + ( 3.6 ) 2 + ( 2.1 ) 2 + 15 ( 1.6 ) 2 + ( 2.1 ) 2 + ( 1.1 ) 2 + ( 0.1 ) 2 + ( 6.1 ) 2 + ( 5.1 ) 2 + ( 2.1 ) 2 + ( 1.1 ) 2 + ( 0.9 ) 2
= 170.18 15 = 11.34 =\dfrac{170.18}{15}=11.34 = 15 170.18 = 11.34
(C) Standard deviation of sampling distribution of means is given by
=variance = 11.34 = 3.368 \sqrt{\text{variance}}=\sqrt{11.34}=3.368 variance = 11.34 = 3.368