Table 5.5 reports that the 95% confidence interval for the comparison of mean corn size at 12 months between the corn plaster and scalpel groups is: −1.7 to −0.2 mm.

Which (if any) of the following statements is CORRECT?

A. The above 95% confidence interval definitely contains the true population mean difference in corn size at 12 months between the corn plaster and scalpel groups.

B. The 95% confidence interval is calculated as ±3 standard errors away from the mean difference.

C. There is a probability of 0.95 that the population mean difference in corn size at 12 months between the corn plaster and scalpel groups lies between −1.7 and −0.2 mm.

D. The 95% confidence interval does not contain the true population mean difference in corn size at 12 months between the corn plaster and scalpel groups.

E. The above 95% confidence interval is likely to contain the true population mean difference in corn size at 12 months between the corn plaster and scalpel groups.

Table 5.5

Transcribed Image Text:

Corn plaster Scalpel Size of (n = (n = Mean 95% confidence index 101) 101) interval corn Mean SD Mean SD SD Difference Lower Upper P-value (mm) Baseline 3.9 (1.7) 3.8 (1.8) 3 1.7 (1.5) 2.7 (2.3) -1.0 -1.5 -0.5 months 6 1.7 (1.6) 2.4 (2.2) -0.7 -1.2 -0.2 months 9 1.7 (1.6) 2.2 (2.1) -0.5 -1.2 0.1 months 12 1.3 (1.6) 2.3 (2.2) -1.0 -1.7 -0.2 0.01 months