Suppose that an airline quotes a flight time of 2 hours, 10 minutes between two cities. Furthermore, suppose that historical flight records indicate that the actual flight time between the two cities, x, is uniformly distributed between 2 hours and 2 hours, 20 minutes (uniform distribution). Letting the time unit be one minute, What is the mean? What is the standard deviation? Find P(125 ≤ x ≤ 135) (between 125 minutes and 135 minutes).

Assume that final exam scores in a given course are approximately normally distributed with a mean of 75 and a standard deviation of 10 points. In a class of 200 students, how many would you expect to fail the exam (i.e., score less than 60) (note: scores can only be approximately normally distributed, because the minimum score is 0, but this should not alter the answer, given how large the mean is relative to the standard deviation).

A standardized exam’s score are normally distributed. In a recent year, the mean test score was 1477 and the standard was 315. The test scores of four students selected at random 1860 1230, 2160, and 1360. Find the Z- score that correspond to each value and determine wether any of the values are unusual. The Z-score for 1860 is-The Z-score for 1230 is-The Z-score for 2160 is-The Z-score for 1360is-

The average American gets a haircut every 34 days. Is the average smaller for college students? The data below shows the results of a survey of 15 college students asking them how many days elapse between haircuts. Assume that the distribution of the population is normal. 35, 23, 32, 38, 31, 39, 35, 25, 30, 36, 40, 27, 23, 32, 25 What can be concluded at the the a = 0.10 level of significance level of significance? a. For this study, we should use Select an answer b. The null and alternative hypotheses would be: Ho: ?v Select an answerv Hi: ?vSelect an answerv c. The test statistic ?v = (please show your answer to 3 decimal places.) d. The p-value = (Please show your answer to 3 decimal places.) e. The p-value is 2v a f. Based on this, we should Select an answerv the null hypothesis. g. Thus, the final conclusion is that.. O The data suggest the population mean is not significantly lower than 34 at a = 0.10, so there M 24 3. 4. 5 6. 7 EU

Jeremiah earned a score of 530 on Exam A that had a mean of 450 and a standard deviation of 40. He is about to take Exam B that has a mean of 63 and a standard deviation of 20. How well must Jeremiah score on Exam B in order to do equivalently well as he did on Exam A? Assume that scores on each exam are normally distributed.

A population has a mean of u=50 and a standard deviation of 0=10. If 3 points were added to every score in the population, what would be the new values for the mean and standard deviation?

Use the formula to find the standard error of the distribution of differences in sample means, x¯1-x¯2.Samples of size 115 from Population 1 with mean 94 and standard deviation 14 and samples of size 85 from Population 2 with mean 75 and standard deviation 17Round your answer for the standard error to two decimal places.standard error = Enter your answer in accordance to the question statement

Assume that we have made 10 repeated measurements of a quantity, and as a result the error assigned to the “best estimate” of the mean is 6. If we then expand our data set to a total of 20 measurements, the error in the mean will reduce to just 3. True or False

Suppose that the mean systolic blood pressure for women over age seventy is 131 mmHg (millimeters of mercury), with a standard deviation of 9 mmHg. Suppose that the blood pressures are normally distributed. Complete the following statements. (a) Approximately? mmHg and 140 mmHg. of women over seventy have blood pressures between 122 (b) Approximately 95% of women over seventy have blood pressures between mmHg and mmHg.