Find the population variance and standard deviation for th 10, 60, 50, 30, 40, 20 → ata set:

Yoonie is a personnel manager in a large corporation. Each month she must review 16 of the employees. From past experience, she has found that the reviews take her approximately four hours each to do with a population standard deviation of 1.2 hours. Let Χ be the random variable representing the time it takes her to complete one review. Assume Χ is normally distributed. Let x¯x¯ be the random variable representing the mean time to complete the 16 reviews. Assume that the 16 reviews represent a random set of reviews. What causes the probabilities in Exercise 7.3 and Exercise 7.4 to be different?

Mason earned a score of 226 on Exam A that had a mean of 250 and a standard deviation of 40. He is about to take Exam B that has a mean of 550 and a standard deviation of 25. How well must Mason 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 standardize exam scores are normally distributed,in a recent year,the mean test scores was 1490,standard deviation was 320,the test sscores four for studentselected at a random are;1940,1249,and 1380.Find the Zscores that correspond to each vale and determine whether any of the values are unusual

Assume that weights of adult females are normally distributed with a mean of 79 kg and a standard deviation of 20 kg. What percentage of individual adult females have weights between 73 kg and 85 kg? If samples of 64 adult females are randomly selected and the mean weight is computed for each sample, what percentage of the sample means are between 73 kg and 85 kg? The percentage of individual adult females with weights between 73 kg and 85 kg is 23.6 % (Round to one decimal place as needed.) The percentage of samples of 64 adult females with mean weights between 73 kg and 85 kg is (Round to one decimal place as needed.)

For a certain type of computers, the length of time between charges of the battery is normally distributed with a mean of 62 hours and a standard deviation of 11 hours. John owns one of these computers and wants to know the number of hours when the computer would have 12%  of its battery life left. Sketch the region in question. Write a sentence describing what your answer represents about the problem's specefics.

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-

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.