Designing footwear to improve posture. Shoe companies like Vionic and Therafit specialize in designing footwear to improve posture and balance. A study on the effectiveness of designed footwear for elderly women was published in Human Factors (December 2019). Twenty-four women between the ages of 60 and 75 were recruited for the study. All 24 were examined under three experimental foot conditions (without socks): barefoot (condition A), wearing a designed texture insole (condition B), and wearing a designed texture insole with an arch support. A key variable for determining balance was the range of the center of pressure (COP), measured in millimeters. The lower the range, the better the balance. Based on summary statistics provided in the study, simulated data on COP ranges were produced. The simulated data, saved in the file, are listed in the next table.

a. One goal is to compare the mean COP ranges for Conditions A and B. Make this comparison using a 90% confidence interval. What inference can you make?

b. Another objective is to compare the mean COP ranges for Conditions B and C. Make this comparison using a 90% confidence interval. What inference can you make? Condition Subject A B C 1