Question

The following data are for three groups of subjects who are exposed to three different methods of exercise programs. The dependent variable is the number of sit-up. Test the appropriate hypothesis using alpha = .05.

Method A : 20, 18, 14, 16, 13, 19, 12    Method B: 19, 12, 13, 17, 15, 20, 14    Method C: 24, 35, 26, 29, 31, 25, 38

-. State the null hypothesis.



-. Report the result in a statistical term and interpret the results.


-. Do you accept or reject the null hypothesis? Explain why.

Answer 1

The R-code is as follows

x=c(20, 18, 14, 16, 13, 19, 12 )  

y=c( 19, 12, 13, 17, 15, 20, 14)

z=c(24, 35, 26, 29, 31, 25, 38)

e=c(x, y, z)

t=c(1,1,1,1,1,1,1,2,2,2,2,2,2,2,3,3,3,3,3,3,3)

d=data.frame(e, t)

a=aov(e~t,d)

summary(a)

And the Output is as follows

Df Sum Sq Mean Sq F value   Pr(>F)    
t            1  658.3   658.3    24.1 9.74e-05 ***
Residuals   19  519.0    27.3                     
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Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1