11. A study of the trunk flexor muscle strength of 75 girls aged 3 to 7 was reported by Baldauf, K., Swenson, D., Medeiros, J., and Radtka, S., “Clinical assessment of trunk flexor muscle strength in healthy girls 3 to 7,” Physical Therapy, 64, pp.

1203–1208, 1984. With muscle strength graded on a scale of 0 to 5, and with 15 girls in each age group, the following sample means and sample standard deviations resulted.

Test, at the 5 percent level of significance, the hypothesis that the mean trunk flexor strength is the same for all five age groups.

Transcribed Image Text:

Age 3 4 56 7 Sample mean 3.3 3.7 4.1 4.4 4.8 Sample standard deviation .9 1.1 1.1 .9 5