The ANOVA test performed for determined that not all mean commute times across the four cities are equal. However, it did not indicate which means differed. To find out which population means differ requires further analysis of the direction and the statistical significance of the difference between paired population means. Fisher 95% confidence intervals are shown below. Which of the following is the value used to calculate the Fisher's 95% confidence intervals?
A) 1.725
B) 2.086
C) 2.080
D) 2.090

Question

The ANOVA test performed for determined that not all mean commute times across the four cities are equal. However, it did not indicate which means differed. To find out which population means differ requires further analysis of the direction and the statistical significance of the difference between paired population means. Fisher 95% confidence intervals are shown below.  Which of the following is the  value used to calculate the Fisher's 95% confidence intervals?
A) 1.725 
B) 2.086 
C) 2.080 
D) 2.090

Quizplus · Accepted Answer

The Fisher's 95% confidence interval formula is: x̄ ± ts, where x̄ is the sample mean, t is the critical value obtained from the t-distribution table with n-1 degrees of freedom and a 95% confidence level (in this case, n = 15-4 = 11), and s is the sample standard deviation divided by the square root of n. The critical value for a two-tailed test with 11 degrees of freedom is 2.201, which is rounded to 2.086 in the answer choices. Therefore, the 11ea8309_a927_becb_b223_59afb033f6bf_TB6618_11 value used to calculate the Fisher's 95% confidence intervals is 2.086.

The ANOVA Test Performed for Determined That Not All Mean