You wish to test the following claim (H) at a significance level of a = 0.005. Trl = Inl:°H You believe both populations are normally distributed, but you do not know the standard deviations for either. And you have no reason to believe the variances of the two populations are equal You obtain a sample of size nj = 23 with a mean of a1 = 86.6 and a standard deviation of s = 19.1 from the first population. You obtain a sample of size no = 20 with a mean of a- 96.5 and a standard deviation of s2 = 7.1 from the second population. a. What is the test statistic for this sample? test statistic = Round to 3 decimal places. b. What is the p-value for this sample? For this calculation, use . p-value = Use Technology Round to 4 decimal places.

The mileage in miles per gallon of several cars when they were new and when they were 3 years old is listed below. New 27 17 33 28 24 18 22 20 29 3 years 24 15 29 25 22 16 20 18 26 The mean of the sample of new car mileages is x = 23.9 with a sample standard deviation of sx 5.2, and The mean of the sample of three year old car mileage is ỹ = 21.4 with a sample standard deviation of sy = 4.6. The linear correlation coefficient is r = 0.998, which suggests linear correlation. Find the regression line and use it to predict the mileage a car will have after 3 years, if it gets 26 miles per gallon when it is new.

Rush

Do the mean weights of male college freshmen and male college seniors differ? There are arguments for and against this question. The mean weight, μx of college freshmen will be compared to the mean weight, My of college seniors. The true values of Mx and My are unknown. It is recognized that the true standard deviations are x = 13 for male college freshmen and dy = 24 for male college seniors. We take a random sample of m = 431 college freshmen and a random sample of n=289 college seniors. The mean weights were x = 178 for male college freshmen and y = 185 for male college seniors. Assuming independence between the samples and assuming the weights are normally distributed we would like to estimate My - My. a) What is the standard deviation of the distribution of x?[ b) What is the standard deviation of the distribution of x-y? c) Create a 95% confidence interval for Mx - Hy? d) What is the length of the confidence interval in part c) ? e) If we let n stay at 289 but vary m, what is the…

The life of a butterfly is normally distributed with a mean of 50 days. You took a random sample of 25 such butterflies. The mean life for this sample is 47 days a standard deviation of 3 days. At α = 0.05. a. Test to see if the average life of a butterfly is different from 50 days. b. Your friend believes that the life of a butterfly is less than 50 days. Is she correct?

Do question 1

Step 1 of 3. State the null and alternative hypotheses for the test.   Step 2 of 3. Compute the value of the test statistic. Round your answer to three decimal places   Step 3 of 3. Draw a conclusion and interpret the decision.

There are many situations in which we want to compare means from populations having standard deviations that are equal. This method applies even if the standard deviations are known to be only approximately equal. Consider a report regarding average incidence of fox rabies in two regions. For region I, n1 = 16, x1 ≈ 4.73, and s1 = 2.84 and for region II, n2 = 15, x2 ≈ 3.93, and s2 = 2.45. The two sample standard deviations are sufficiently close that we can assume ?1 = ?2. Use the method of pooled standard deviation to consider the report, testing if there is a difference in population mean average incidence of rabies at the 5% level of significance. (Round your answer to three decimal places.) t =

"A fitness coach woud like to determine whether her aerobic fitness intervention leads to a significant increase or decrease in the one rep max (i.e., heaviest possible weight that can be lifted once) for deadlifts in her group of athletes (n = 13). She finds that the mean difference = 3 lbs, with a sum of squared deviation (SS) = 84. Calculate the t-statistic the fitness coach would observe given this data. (Be sure to round your answer to the second decimal place)."

The average score on a statistics test was 2.21 with a standard deviation of 0.88. The teacher suspects that the exam was very difficult; Based on the above, you want to adjust the scores so that the mean is 3.37 and the standard deviation is 0.25. Compute the values ​​a and b such that the fit of type aX+b gives the desired mean and variance? Calculate: a= Answer b= Answer TIP: Use expected value and variance properties.