large software development firm recently relocated its facilities. Top management is interested in fostering good relations with their new local community and has encouraged their professional employees to engage in local service activities. They want to test if the firm's professionals volunteer an average of  15 hours per month or not (two-sided test). Suppose 41 professional employees are randomly selected. This sample yields a mean of 15.2 hours and a standard deviation of 1.8 hours. The 95% confidence interval is: A. 10.65 to 20.22 hours B. 13.88 to 14.29 hours C. 11.98 to 18.02 hours D. 14.63 to 15.77 hours

Q: Before After 6.9 6.3 3.6 2.1 7.3 7.1 12.8 8.6 8.5 8.2 10.1 6.4 8.4 3.9 5.2 2.1

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