Question

Hallux abducto valgus (call it HAV) is a deformation of the big toe that often requires surgery. Doctors used X-rays to measure the angle (in degrees) of deformity in 38 consecutive patients under the age of 21 who came to a medical center for surgery to correct HAV. The angle is a measure of the seriousness of the deformity. Here are the data.

27 22 17 32 16 28 23 14 30 35 21 21 37 22 48 27 13 27 26 33 26 16 27 28 32 19 30 25 20 40 30 19 33 14 20 21 19 25

It is reasonable to regard these patients as a random sample of young patients who require HAV surgery. Given a 95% confidence interval for the mean HAV angle in the population of all such patients, find the following.

x = °

s = °

Confidence Interval: ° to °

Conclusion (choose one):

-The mean HAV angle among such patients will always be outside this interval 95% of the time.

-We are 95% confident that the mean HAV angle among such patients is within this interval.

-The mean HAV angle among such patients will always be within this interval 95% of the time.

-We are 95% confident that the mean HAV angle among such patients is outside this interval.

Answer 1

The statistical software output for this problem is:

From above output:

x = 25.34

s = 7.66

Confidence interval: 22.82 to 27.86

We are 95% confident that the mean HAV angle among such patients is within this interval.