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A 2016 study reported in Science magazine stated that college math teachers scored a mean of 3.4 points for providing feedback to students on their work. Assume the sample size was 26 and the sample standard deviation was 1.5. Give the best point estimate for the population and construct a 99% confidence interval for the true population mean, stating the null and alternative hypothesis. Show your work

User Vennsoh
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Final answer:

The best point estimate for the population mean is the sample mean, 3.4. A 99% confidence interval is constructed using the sample mean, sample standard deviation, and the appropriate t-value. The null and alternative hypotheses for testing the true population mean are defined as equals to or not equal to the sample mean, respectively.

Step-by-step explanation:

The best point estimate for the population mean is the sample mean, which in this case is 3.4 points for providing feedback. To construct a 99% confidence interval for the true population mean, we use the t-distribution because the sample size is less than 30. The formula for the confidence interval is given by = sample mean ± (t-value * (sample standard deviation/sqrt(sample size))). With a sample size of 26 and a standard deviation of 1.5, and using the t-distribution table for a degree of freedom of 25 (n-1) at the 99% confidence level, we can find the appropriate t-value. To set up the hypotheses for testing, we can state that the null hypothesis (H0) would be that the population mean is equal to the sample mean (μ = 3.4) and the alternative hypothesis (H1) would be that the population mean is not equal to 3.4 (μ ≠ 3.4). Once the appropriate t-value is found, plug it into the formula to get the confidence interval. For example, if the t-value is 2.796, the confidence interval would be 3.4 ± (2.796 * (1.5/sqrt(26))), which would need to be calculated to get the confidence interval range.

User MrClean
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