The following results are for independent random samples taken from two populations. Sample 1 Sample 2 n1 = 20 n2 = 30 x1 = 22.7 x2 = 20.1 s1 = 2.6 s2 = 4.4 (a) What is the point estimate of the difference between the two population means? (Use x1 − x2.) (b) What is the degrees of freedom for the t distribution? (Round your answer down to the nearest integer.) (c) At 95% confidence, what is the margin of error? (Round your answer to one decimal place.) (d) What is the 95% confidence interval for the difference between the two population means? (Use x1 − x2. Round your answers to one decimal place.)
Added by Elisa P.
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$\bar{x}_1 - \bar{x}_2 = 22.7 - 20.1 = 2.6$ So, the point estimate is $\boxed{2.6}$. (b) To find the degrees of freedom for the t-distribution, we can use the formula: $df = \frac{(\frac{s_1^2}{n_1} + \frac{s_2^2}{n_2})^2}{\frac{(\frac{s_1^2}{n_1})^2}{n_1 - 1} Show more…
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The following results are for independent random samples taken from two populations. Sample 1 Sample 2 n1 = 20 n2 = 30 x1 = 22.6 x2 = 20.1 s1 = 2.6 s2 = 4.4 (a) What is the point estimate of the difference between the two population means? (Use x1 - x2.) (b) What is the degrees of freedom for the t distribution? (Round your answer down to the nearest integer.) (c) At 95% confidence, what is the margin of error? (Round your answer to one decimal place.) (d) What is the 95% confidence interval for the difference between the two population means? (Use x1 - x2. Round your answers to one decimal place.)
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