Many studies have suggested that there is a link betweenexercise and healthy bones. Exercise stresses the bones and thiscauses them to get stronger. One study examined the effect ofjumping on the bone density of growing rats. There were threetreatments: a control with no jumping, a low-jump condition (thejump height was 30 centimeters), and a high-jump condition (60centimeters). After 8 weeks of 10 jumps per day, 5 days per week,the bone density of the rats (expressed in mg/cm3 ) was measured.Here are the data. data190.dat
(a) Make a table giving the sample size, mean, and standarddeviation for each group of rats. Consider whether or not it isreasonable to pool the variances. (Round your answers for x, s, ands_(x^^\_) to one decimal place.)
Group n x^^\_ s s_(x^^\_)
Control
Low jump
High jump
(b) Run the analysis of variance. Report the F statistic withits degrees of freedom and P-value. What do you conclude? (Roundyour test statistic to two decimal places and your P-value to threedecimal places.)
F =
P =
Conclusion: There is statistically no/a significant differencebetween the three treatment means at the ? = .05 level.
obs group g density1 Control 1 6162 Control 1 6133 Control 1 6094 Control 1 6195 Control 1 6646 Control 1 6027 Control 1 5718 Control 1 5859 Control 1 60010 Control 1 60911 Lowjump 2 62312 Lowjump 2 62013 Lowjump 2 62214 Lowjump 2 65315 Lowjump 2 62216 Lowjump 2 63417 Lowjump 2 64718 Lowjump 2 63619 Lowjump 2 64220 Lowjump 2 66021 Highjump 3 63922 Highjump 3 61123 Highjump 3 58624 Highjump 3 62225 Highjump 3 61026 Highjump 3 60527 Highjump 3 62628 Highjump 3 63029 Highjump 3 60530 Highjump 3 640
