Sample Mean:X =ΣΧWhereΣ= sum (or add up)sample mean= total number of scores, or the sample size=nFor a population, mean is represented by the Greek letter mu (µ)Population Variance:g² = E (X -µ)²NSample Variance:s? = E(X-Xyn - 1Remember that the standard deviation (o or s) is the square root (v ) of the variance.Z Score (for one score/individual):Z = X -µZ Score: One Sample Z test:Z == mean of sampleu = mean of populationO = standard deviation of populationn = sample sizeIn = square root of sample size 4. A researcher in Economics believes that the mean income of psychiatrists is now more than $65 thousand peryear. Which is the correct set of hypotheses to test this belief?a. Ho: µ > 65000; HA: µ < 65000b. Ho: μ < 65000; ΗA: μ > 65000c. Ho: µ = 65000; HA: µ ± 65000d. Ho: µ will be proven to come from a different distribution; HA: µ will be proven to come from the distributionwith a mean of 65000

Answered: 4. A researcher in Economics believes…

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

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Suppose 1 in 100 workers die on the risky job each year, while no workers die on the safe job each year. Moreover, the average salary for the safe job is $50,000 and for the risky job is $60,000. a. What is the compensating wage differential of the risky job? b. What is the implied statistical value of a life of a worker on the risky job? Please help ?
Andrew plans to retire in 40 years. He plans to invest part of his retirement funds in stocks, so he seeks out information on past returns. He learns that over the entire 20th century, the real (that is, adjusted for inflation) annual returns on U.S. common stocks had mean 8.7% and standard deviation 20.2%. The distribution of annual returns on common stocks is roughly symmetric, so the mean return over even a moderate number of years is close to Normal. What is the probability (assuming that past pattern of variation continues) that the mean annual return on common stocks over the next 40 years will exceed 10%? What is the probability that the mean return will be less than 5%?
3. ACT scores are roughly Normal with mean 20.8 and standard deviation 4.8, and SAT scores are roughly Normal with mean 1026 and standard deviation 209. Some students take both. For those students, the correlation between the two scores is 0.72. a. What's the equation of the straight line that you'd use to predict ACT scores based on SAT scores? b. I got a 1300 on the SAT, and I'm planning to take the ACT. Predict what I might get, c. What's the equation of the straight line that you'd use to predict SAT scores based on ACT scores? d. My friend got a 27 on the ACT, and she's planning to take the SAT. Predict what she might get. e. How come you're predicting both that I'll do worse than her on the ACT and that she will do worse than me on the SAT? 4. Draw a simple random nlc of size 15 from the labels 40os01, 402.
Answers 0.826 0.779 0. 221 0. 174
3. What percentage of College students have made at least one online purchase in the last three months? To answer this question, a market researcher surveyed 200 college students. Of those surveyed, 76 said that they had made at least one online purchase (a.) What is the parameter of interest in this study? (b.) Calculate the corresponding point estimate of the population proport
1. Find the p-value. (Round to three or more decimal places.) 2. At the 0.01 level of significance, can the doctor conclude that the mean recovery time of patients who have the new procedure is less than the mean recovery time of patients who have the standard procedure?
1. The data in Table 7–6 were collected in a clinical trial to evaluate a new compound designed to improve wound healing in trauma patients. The new compound was com- pared against a placebo. After treatment for 5 days with the new compound or placebo, the extent of wound healing was measured. Is there a difference in the extent of wound healing between the treatments? (Hint: Are treatment and the percent wound healing independent?) Run the appropriate test at a 5% level of significance. Use the data in Problem 1. Pool the data across the treatments into one sample of size n = 250. Use the pooled data to test whether the distribution of the percent wound healing is approximately normal. Specifically, use the following distribution 30%, 40%, 20%, and 10% and a = 0.05 to run the appropriate test. Percent Wound Healing Treatment 0-25% 26-50% 51-75% 76-100% New compound (n=125) 15 37 32 41 Placebo (n=125) 36 45 34 10
Iron-deficiency anemia is an important nutritional healthproblem in the United States. A dietary assessment wasperformed on 51 boys 9 to 11 years of age whose familieswere below the poverty level. The mean daily iron intakeamong these boys was found to be 12.50 mg with standarddeviation 4.75 mg. Suppose the mean daily iron intakeamong a large population of 9- to 11-year-old boys fromall income strata is 14.44 mg. We want to test whether themean iron intake among the low-income group is differentfrom that of the general population. Problem a) State the hypotheses that we can use to considerthis question.Problem b) Carry out the hypothesis test in Problem a using the critical-value method with an α level of 0.05, and summarize your findings. Problem c) What is the p-value for the test conducted in Problem b?
2
2. The following passage is from a paper. Also significant was the proportion of males and their water consumption (8 oz. servings) compared to females (X2 = 8.136, P-value = 0.087). Males came closer to meeting recommended daily water intake (64 oz. or more) than females (29.8% vs. 20.9%). This statement was based on carrying out a chi-square test of homogeneity using data in a two-way table where rows corresponded to sex (male, female) and columns corresponded to number of servings of water consumed per day, with categories none, one, two to three, four to five, and six or more. A) What hypotheses did the researchers test? H0: Sex and number of servings of water consumed per day are not independent. Ha: Sex and number of servings of water consumed per day are independent. H0: The proportions falling into each of the water categories are the same for both sexes.Ha: The proportions falling into each of the water categories are not the same for both sexes. H0: The…

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