CPUS made of two different materials are tested to see how they effect the processor speed of a computer. Specifically, material 1 is currently in use, but material 2 is acceptable. Since material 2 is cheaper, it should be adopted, providing it does not change the process yield. A test is run and results are obtained as follows. n = 8 8. 2.39 2.98 92.255 X2 92.733 Construct a 99% confidence interval for the difference of means under equal variance case.

Mechanical components are being produced continuously. A quality control program for the mechanical components requires a close estimate of the proportion defective in production when all settings are correct. 1020 components are examined under these conditions, and 27 of the 1020 items are found to be defective. (a) Find a point estimate of the proportion defective. (b) Find a 95% two-sided confidence interval. (c) Find an upper limit giving 95% level of confidence that the true proportion defective is less than this limiting value. Use Excel in parts (b) and (c).a need.

Suppose we are testing brake light reaction times for a new brake light design. The current design (we will call it the old design) is known to have an average reaction time of 0.8 seconds. A random sample of 50 drivers are tested on the new design, and the 50 drivers have an average reaction time of 0.76 seconds, with a 95% confidence interval of (0.66, 0.86) seconds. Write a few sentences to explain how we should interpret this data. Explain what the null hypothesis is here, whether we rejected the null, or failed to reject, and also what the implications are.

I'm confused with the R code, I'm supposed to do a 90% confidence interval at t=0.01.

A study was conducted to determine if the percent of women who received financial aid is different form the percentage of men who receive financial aid. A random sample of students revealed the results shown in the table. Using (a=0.01), is there significant evidence to reject the null hypothesis? women men sample size number receiving aid 200 250. 300 225 a. Find the 90% confidence interval for the difference in financial aid rates between men and women and interpret this interval in the context of the problem. b. Write the two hypotheses for the problem. c. Compute the appropriate statistical hypothesis test and report the test statistic and p-value. d. Write the conclusion for the problem regarding the null hypothesis using statistical language.

A recent poll indicated that 42% of men supported raises taxes to fund additional park services.   The poll also found that 64% of women supported such a tax.  The sample consisted of 390 men and 420 women.   Construct a 95% confidence interval around the difference in proportions.

A recent poll indicated that 42% of men supported raises taxes to fund additional park services.   The poll also found that 64% of women supported such a tax.  The sample consisted of 1300 men and 1350 women.   Construct a 99% confidence interval around the difference in proportions.

In a​ survey, 12001200 adults in a certain country were asked how many hours they worked in the previous week. Based on the​ results, a​ 95% confidence interval for mean number of hours worked was lower​ bound: 37.837.8 and upper​ bound: 39.539.5. Which of the following represents a reasonable interpretation of the​ result? For those that are not​ reasonable, explain the flaw. Complete parts​ (a) through​ (d) below.​(a) There is a​ 95% chance the mean number of hours worked by adults in this country in the previous week was between 37.837.8 hours and 39.539.5 hours. A.Flawed. This interpretation implies that the population mean varies rather than the interval. B.Correct. This interpretation is reasonable. C.Flawed. This interpretation makes an implication about individuals rather than the mean. D.Flawed. This interpretation implies that the mean is only for last week. Click to select your answer and then click Check Answer.3

17.18  4S overall mortality. The 4S study introduced in Exercise 17.17 also tallied deaths due to any cause. The treatment group experienced 182 deaths (n1 = 2221) and the control group experienced 256 deaths (n2 = 2223). Compare the mortality experience in the two groups in the form of a relative risk and 95% confidence interval.

Prothrombin time is a measure of the clotting abil-ity of blood. For 10 rats treated with an antibiotic and 10 control rats, the prothrombin times (in seconds) werereported as follows: see photo (a) Construct a 90% confidence interval for the differencein population means. (Assume that the twopopulations from which the data came are normallydistributed.)(b) Why is it important that we assume that the twopopulations are normally distributed in part (a)? (c) Interpret the confidence interval from part (a) in thecontext of this setting.