Bakery A X1 = 1872 cal Construct a 95% confidence interval for u, - 42 with the sample statistics for mean Bakery B X2 = 1705 cal calorie content of two bakeries' specialty pies and confidence interval construction formula below. Assume the populations are approximately normal with equal variances. s1 = 165 cal S2 = 190 cal n, = 11 n2 = 17 (*1 -*2) - tô + - 대- 내> n. Confidence interval when variances are equal (n, - 1) s? • (^2 - 1) s? where ô = and d.f. =n, +ng - 2 n, +n2 - 2 Enter the endpoints of the interval. (Round to the nearest integer as needed.) . 대 - 내>| |-|&

chester butchery supplies vienna sausages in the entire kzn province. a meat packer is investigating the marked mass shown on vienna sausages. a pilot study showed a mean of 11.8kg per pack and a variance of 0.49kg. how many packs should be sampled in order to be 92% confident that the sample mean will differ by at most 0.2kg.

For each scenario, indicate whether the parameter of interest is one proportion , a difference in two proportions , one mean (μ), a difference in means from separate samples , or the mean difference from matched pairs data,  .  Each answer can be selected once, more than once, or not at all. A tire manufacturer tested the braking performance of one of its tire models on a test track, interested in how tires perform under both wet and dry pavement conditions. The company tried the tires on 18 different car models, recording the stopping distance for half of them on wet pavement and the other half of dry pavement.   Student Computing Services surveys a random sample of students to compare the percent of students that have PCs to the percent of students that have Macs.    Married couples are asked about the number of hours of sleep they get each night. We want to see if husbands get more sleep than their wives.   36 of 75 patients receiving a treatment experienced pain relief, while only…

A researcher decides to measure anxiety in group of bullies and a group of bystanders using a 23-item, 3 point anxiety scale.  Assume scores on the anxiety scales are normally distributed and the variance among the group of bullies and bystanders are the same. A group of 30 bullies scores an average of 21.5 with a sample standard deviation of 10 on the anxiety scale.  A group of 27 bystanders scored an average of 25.8 with a sample standard deviation of 8 on the anxiety scale. You do not have any presupposed assumptions whether bullies or bystanders will be more anxious so you formulate the null and alternative hypothesis based on that.

A researcher wants to measure average cardiovascular health of university students and compare those scores to the average scores in the general population. Assuming that population variance is known, what statistical test is most appropriate for this study?        independent-samples t-test     single-sample t-test     z-test for sample mean     related-samples t-test

A basketball coach believes that the variance of the heights of adult male basketball players is different from the variance of heights for the general population of men. The sample variance of heights, measured in inches, for a random sample of 19 basketball players is 14.22. The sample variance for a random sample of 18 other men is 34.49. Assume that both population distributions are approximately normal and test the coach’s claim using a 0.10 level of significance. Does the evidence support the coach’s claim? Let male basketball players be Population 1 and men in general be Population 2.   Step 1 of 3:  State the null and alternative hypotheses for the test. Fill in the blank below. H0: σ21=σ22: Ha: σ21⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯σ22 Step 2 of 3:  Compute the value of the test statistic. Round your answer to four decimal places. Step 3 of 3:  Draw a conclusion and interpret the decision.

The valve pressure was tested on 250 engines and the mean pressure was 5.9 lbs/square inch. Assume the variance is known to be 0.36. If the valve was designed to produce a mean pressure of 5.8 lbs/square inch, is there sufficient evidence at the 0.02 level that the valve performs about the specifications?

An automobile manufacturer has given its van a 50.6 miles/gallon (MPG) rating. An independent testing firm has been contracted to test the actual MPG for this van since it is believed that the van has an incorrect manufacturer's MPG rating. After testing 220 vans, they found a mean MPG of 50.5. Assume the population variance is known to be 1.69. A level of significance of 0.01 will be used. Find the P-value of the test statistic. you may write the P-value as a range using interval notation, or as a decimal value rounded to four decimal places.