In a sample of 20 participants,a researcher estimates the 99% CI for a sample with a mean of M_D = 3.7 and an estimated standard error for the difference scores (S_MD)of 0.2.What is the confidence interval at this level of confidence? A) 99% CI 3.5, 3.9 B) 99% CI 3.2, 4.2 C) 99% CI 3.1, 4.3 D) There is not enough information to answer this question.

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Quizplus · Accepted Answer

The 99% confidence interval is calculated as M_D ± (critical t-value) * S_MD. With 19 degrees of freedom (n-1), the critical t-value is approximately 2.861. Thus, the interval is 3.7 ± (2.861 * 0.2), which is approximately 3.1 to 4.3.

In a Sample of 20 Participants,a Researcher Estimates the 99