Many studies have suggested that there is a link between exercise and healthy bones. Exercise stresses the bones and this causes them to get stronger. One study examined the effect of jumping on the bone density of growing rats. There were three treatments: a control with no jumping, a low-jump condition (the jump height was 30 centimeters), and a high-jump condition (60 centimeters). 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.data43.dat

(a) Make a table giving the sample size, mean, and standard deviation for each group of rats. Consider whether or not it is reasonable to pool the variances. (Round your answers forx,s, andto one decimal place.)

Group n xbar s s xbar

control

low jump

high jump

(b) Run the analysis of variance. Report theFstatistic with its degrees of freedom andP-value. What do you conclude? (Round your test statistic to two decimal places and yourP-value to three decimal places.)

F=

P=

Conclusion:There is (a or no) statistically significant difference between the three treatment means at the= .05 level.