QUESTION 24 To estimate the average time it takes to assemble a certain computer component, the industrial engineer at an electronics firm timed 25 technicians in the performance of this task, getting a mean of 12.5 minutes anda standard deviation of 2 minutes. Construct a 98% confidence interval of the actual average time required to do the job assuming that the actual time follows a normal distribution. O (11.678, 13.322) O (11.570, 13.430) O (11.503, 13.497) O (11.631, 13.369)

Suppose that for the past several decades, daily precipitation in Seattle, Washington has had a mean of 2.4 mm and a standard deviation of 11.4 mm. Researchers suspect that in recent years, the mean amount of daily precipitation has changed, so they plan to obtain data for a random sample of 195 days over the past five years and use this data to conduct a one-sample ?z‑test of ?0:?=2.4H0:μ=2.4 mm against ?1:?≠2.4H1:μ≠2.4 mm, where ?μ is the mean daily precipitation for the last five years. Although they realize that rainfall does not follow a normal distribution, they feel safe using a ?z‑test because the sample size is large. The researchers want to know what the power of this test is to reject the null hypothesis at significance level ?=0.05α=0.05 if the actual mean daily precipitation is 2.6 mm or more. Computing power by hand requires two steps. The first step is to use a significance level of 0.05 to determine the values of the sample mean for which they will reject their null…

In a sample of 14 randomly selected high school seniors, the mean score on a standardized test was 1197 and the standard deviation was 166.9. Further research suggests that the population mean score on this test for high school seniors is 1018. Does the t-value for the original sample fall between -to.95 and to.95? Assume that the population of test scores for high school seniors is normally distributed. fall between -to.95 and to.95 because to.95 = The t-value of t= (Round to two decimal places as needed.) C

A population has a mean of 200 and a standard deviation of 90. Suppose a simple random sample of size 125 is selected and is used to estimate μ. Use z-table. a. What is the probability that the sample mean will be within 18 of the population mean (to 4 decimals)? b. What is the probability that the sample mean will be within 16 of the population mean (to 4 decimals)?