Question

Player A    B       C         D         E         F       G         H       I        J       K      

Reported weight 68      74     66.5    69       68      71       70     70      67     68      70       

Measured weight 66.8   73.9   66.1   67.2     67.9   69.4   69.9   68.6   67.9   67.6 68.8

Height Difference 1.2      0.1     0.4    1.8      0.1      1.6      0.1     1.4   -0.9    0.4     1.2

Mean d = 0.672727    Standard Deviation S = 0.825943    Sample Size   n = 11

If you are asked to build a 95% confidence interval for µ_d , which critical value would you use?

(i)     ta/2 = 2.201 for 11 d.f.                 (ii)    ta/2 = 2.228 for 10 d.f.    

(iii)   ta = 1.796 for 11 d.f.                  (iv)    ta = 1.812 for 10 d.f.

Then the 95% CI you would calculate is:   (             ≤      µ_d   ≤                )

Answer 1

In confidence interva we use value for two tail

so critical value would be used

(ii)    ta/2 = 2.228 for 10 d.f.    Answer

n=11

95% confidence interval for µ_d

Mean d ta/2 for 10 d.f. *S/sqrt (n)

0.672727   2.228*0.825943/ sqrt(11)

0.672727  0.55484148

{0.11788855, 1.22756848)

( 0.11788855  ≤      µ_d   ≤  1.22756848  ) Answer