The Annual Dividend Rates for a Random Sample of 16 $\pm$

Multiple Choice

The annual dividend rates for a random sample of 16 companies in three different industries, utilities, banking, and insurance were recorded. The ANOVA comparing the mean annual dividend rate among three industries rejected the null hypothesis that the dividend rates were equal. The Mean Square Error (MSE) was 3.36. The following table summarized the results:
Compare the mean annual dividend rate for companies in the utilities and insurance industries and construct the 95% confidence interval.

A) 5.78 $\pm$ 2.160 * 2.40
B) 5.78 $\pm$ 2.120 * 2.40
C) 5.78 $\pm$ 2.160 * 1.11
D) 5.78 $\pm$ 2.120 * 1.11