MATH 533 Week 3 Quiz (Summer 2019)
- Question: The ages of a group of 50 women are approximately normally distributed with a mean of 47 years and a standard deviation of 6 years. One woman is randomly selected from the group, and her age is observed.
- Question: Almost all companies utilize some type of year-end performance review for their employees. Human Resource (HR) at a university Health Science Center provides guidelines for supervisors rating their subordinates. For example, raters are advised to examine their ratings for a tendency to the either too lenient or too harsh. According to HR, “if you have this tendency, consider using a normal distribution —-10% of employees (rated) exemplary, 20% distinguished, 40% competent, 20% marginal and 10% unacceptable. “ Suppose you are rating an employee’s performance on a scale of 1 (lowest) to 100 (highest). Also, assume the ratings follow a normal distribution with a mean of 50 and a standard deviation of 12. Complete parts a and b.
- Question 4.6.101: Financial analysts who make forecast of stock prices are categorized as either “buy-side” analysts or “sell-side” analysts. Te mean and standard deviation of the forecast errors for both types of analysts are shown in the table to the right. Assume that the distribution of forecast errors are approximately normally distributed.
- Question 4.6.102: The ages of group of 50 women are approximately normally distributed with a mean of 50 years and a standard deviation of 6 years. One woman is randomly selected from the group, and her age is observed.
- Question 4.6.109: Personnel tests are designed to test a job application’s cognitive and/or physical abilities. A particular dexterity test is administered nationwide by a private testing service. It is known that for all tests administered last year, the distribution of scores was approximately normal with mean 73 and standard deviation 6.7.
- Question 5.3.16: Suppose a random sample of n = 100 measurements is selected from a population with mean µ and standard deviation σ. For each of the following values of µ and σ, give the values of µx, σx.
- Question 3.18: A random sample of n = 49 observations is drawn from a population with a mean equal to 23 and a standard deviation equal to 14.
- Question 3.19: _- A random sample of n = 81 observations is drawn from a population with a mean equal to 49 and a standard deviation equal to 36.
- Question 3.24: The average salary for a certain profession is $80,500. Assume that the standard deviation of such salaries is $27,500. Consider a random sample of 72 people in this profession and let x̄ represent the mean salary for the sample.
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