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# Hypothesis Testing

### Statistics - One Tailed Test for Small Samples Right Tailed Test

Question : The mean score on a standardized psychology test is supposed to be 50. Believing that a group of psychologists will score higher, we test a random sample of 11 psychologists. Their mean score is 45 with s=3. Test at a level of significance of 1%.

### Inspection of student data generated during pre/post treatment surveys shows that among 10 subjects, 7 had higher scores after an experimental treatment, 2 had lower scores, and 1 score did not change. Using the traditional method of hypothesis testing, we need to determine if the experimental course has any effect. Use an alpha level of .01. If the computed test statistic is 2.36, what is the critical value (2 decimal places of significance, and did the experimental course make a difference (Yes or No))? Students at the University of Arkansas randomly selected 217 student cars and found that they had ages with a mean of 7.89 years and a standard deviation of 3.67 years. They also randomly selected 152 faculty cars and found that they had ages with a mean of 5.99 years and a standard deviation of 3.65 years. Use a 0.01 significance level to test the claim that student cars are older than faculty cars. What are the critical value (3 places of significance) and t score (2 places of significance)? Are student cars older (Yes or No)? A U.S. Department of Justice report included the claim that "in spouse murder cases, wife defendants were less likely to be convicted than husband defendants." Sample data consisted of 277 convictions among 318 husband defendants and 155 convictions among 222 wife defendants. Test the stated claim. Assume Aplha = 0.05. What are the Critical value and z score, each to two decimal places of precision? Do you reject the null hypothesis (Yes or No)?

Inspection of student data generated during pre/post treatment surveys shows that among 10 subjects, 7 had higher scores after an experimental treatment, 2 had lower scores, and 1 score did not change. Using the traditional method of hypothesis testing, we need to determine if the experimental course has any effect. Use an alpha

### Three Statistics Multiple Choice Questions

NNIPS-II was a randomized study of 15,987 infants born alive to 43,559 women who received Vitamin A, Beta-carotene, or a placebo prior to and during pregnancy. (Investigators: Drs. Keith West, Joanne Katz, Parul Christian et al..) Infants were followed for up to 180 days after birth, until death (the event (outcome) being studie

### Binomial Variable and Hypothesis Testing

Using the accompanying probability distribution, find the following values X P(x) 1 .25 2 .27 3 .05 4 .43 a) Mean b) Standard Deviation Assume that the cure rate for a certain drug is 20% and that 15 patients are tested with this drug. Find the following: a) Mean b) Standard Deviation c) P (exactl

### Hypothesis Testing, ANOVA, Lab Comparison

Seven labs were used to measure the amount of chlorpeniramide malcate in tablets. The aim was to study the consistency between the labs and the variability of the measurement process. Each lab makes 10 measurements of a chemical mixture from ground tablets. The ANOVA table is given attached. a) Complete the table. What can yo

### Ecology Club Membership

The advisors of an ecology club at a large college believes that the group consists of 10% freshman 20% sophomores 40% juniors and 30% seniors. The membership for the club this year consisted of 14 freshmen 19 sophomores 51 juniors and 16 seniors. At alpha= 0.1 test the advisors conjecture.

### Multiple choice questions from testing of hypothesis

Part 1 Intelligence quotients (i.e. IQ's) as measured by one intelligence test are known to be normally distributed with a standard deviation of 16. Suppose a random sample of X denote the mean IQ score achieved on the test by 20 people take this intelligence test. Let this sample of 20 people. Suppose that, instead

### Variation of adult heights and weights

A student conducted a study on the height and weight of adult males. She collected data from 40 adult males and found that average height is 68.34 inches with a standard deviation of 14.02 inches, and the average weight is 172.55 lbs. with a standard deviation of 26.33lbs. Based on the above values of the standard deviations,

### Statistics Questions on Sorghum and High School Grades

Statistics Questions. See attached file for full problem description. 4. The attached table shows the data of 77 students on public or private school attendance in the elementary and high school grades. For example, 34 out of 77 students attended both public elementary and public high schools. Test at the 0.05 significanc

### Hypothesis, Population Mean and Proportions

Discuss examples where you would use test of hypothesis at your personal or professional life, in your education or society for the following situations: (a) For two population means and discuss if the example would use large samples or small samples. (b) For two population proportions.

### Interpretation of Statistical Tests

1. The statement that the probability of a Type I error is 0.05 means 1) alpha = 0.05 2) The probability that we are wrong in our decision of rejecting the null hypothesis is 5%. 3) All of the above 4) We decide to reject the null hypothesis at the 0.05 level of significance. 2. A gambler has developed two strateg

### Three statistics questions: interpretation of regression, null hypothesis, degrees of freedom

1. Each year a nationally recognized publication conducts its "Survey of America's Best Graduate and Professional Schools." An academic advisor wants to predict the typical starting salary of a graduate at a top business school using GMAT score of the school as a predictor variable. A simple linear regression of SALARY vers

### Which experimental design was employed? What hypothesis should the newspaper test in order to show that its claim is true? What criterion is used to assess whether the Central Limit Theorem can be applied to this problem?

1. Do motivation levels between Japanese and American managers differ? A randomly selected group of each were administered the Sarnoff Survey of Attitudes Toward Life (SSATL), which measures motivation for upward mobility. The SSATL scores are summarized below: Judging from the way the data were collected, which experimental

### Three multiple choice statistics questions about assumptions and interpretations of statistical tests

1. A national organization has been working with utilities throughout the nation to find sites for large wind machines for generating electric power. Wind speeds must average more than 12 miles per hour (mph) for a site to be acceptable. Recently, the organization conducted tests at a particular site under consideration for a w

### Testing the Hypothesis Given a Standard Deviation

Test the hypothesis that the standard deviation is 10 (use the data below). Provide a 95% confidence interval for the variance. Compute the p value for the test. 101.633 91.169 108.907 102.19 99.485 96.078 112.841 109.448 106.771 90.432 110.971 105.659 100.346 94.768 77.861 86.412 96.465 89.31 90.101 123.1

### Linear Regression, Hypothesis Testing and Probability

1. The basic assumption in linear regression is that the relationship between variables can be approximated by linear relation. Can you think of examples of such relations that you expect to be linear relations? 2. Pick one of the feature hypothesis tests and explain it in everyday language. 3. Consider rolling a pair of d

### Hypothesis Testing: Investment Downturns

The Asian economy faltered during the last few months of 1997. Investors anticipated that the downturn in the Asian economy would have a negative effect on the earnings of companies in the United States during the fourth quarter of 1997. The following sample data show the earnings per share for the fourth quarter of 1996 and the

### A Two-Sample Tests of Hypothesis

Two boats, the Prada (Italy) and the Oracle (U.S.A.), are competing for a spot in the upcoming America's Cup race. They race over a part of the course several times. Below are the sample times in minutes. At the .05 significance level, can we conclude that there is a difference in their mean times? Boat Times (minutes) Prad

### Two-Sample Tests of Hypothesis

Clark Heter is an industrial engineer at Lyons Products. He would like to determine whether there are more units produced on the afternoon shift than on the day shift. A sample of 54 day-shift workers showed that the mean number of units produced was 345, with a standard deviation of 21. A sample of 60 afternoon-shift workers s

### BIOSTATISTICS FOR HEALTH SCIENTISTS

See attached file for full problem description. In a study designed to compare the efficacy of two drugs in lowering blood pressure, patients were paired according to their gender, age and disease severity. Patients within each pair were randomly allocated to one of the two drugs. Summary statistics for the decrease in blood

### Logistic Regression Equation

You conduct a study on the effect of type of defense counsel on the outcome of a criminal trial. You have the information from a random sample of 20 criminal trials on the outcome of the trial (0 = acquitted, 1 = convicted) and type of defense counsel (0 = private, 1 = public defender). With these data, you run a logistic regres

### Statistics for Business and Economics - SPSS software

Please try to include the following three elements for each of the question: ? Hypotheses (both null and alternative hypotheses) ? Analysis (Relevant SPSS printouts or Excel) ? Conclusion (interpretation of data) ? Do not need to outline and examine the assumptions that the chosen statistical technique makes (e.g., the distr

### SPSS computation and Interpretation: Hypothesis testing

SPSS computation and Interpretation: The Asian economy faltered during the last few months of 1997. Investors anticipated that the downturn in the Asian economy would have a negative effect on the earnings of companies in the United States during the fourth quarter of 1997. The following sample data show the earnings per share f

### Testing Hypotheses of AIU Data set

Perform hypothesis testing on one variable's data. (Choose either intrinsic or extrinsic column). I chose the extrinsic Perform a t-test by formulating a null and an alternative statement, choosing an acceptable significance value, selecting the test statistic and determining its value from the sample data, comparing the observ

### Birthday and Oscar Wins Correlation

The author collected data consisting of the month of birth of actors who won Oscars. Use a 0.05 significance level to test the claim that Oscar winning actors are born in different months with the same frequency. Month Jan Feb Mar April May June July Aug Sept Oct Nov Dec Number 9 5 7 14 8 1 7 6 4 5 1 9

### Tests of Hypothesis - Two Populations

Question (1): A random sample of 15 observations from the first population revealed a sample mean of 350 and a sample standard deviation of 12. A random sample of 17 observations from the second population revealed a sample mean of 342 and a sample standard deviation of 15. At the .10 significance level, is there a difference i

### Hypothesis test

Ms. Lisa Monnin is the budget director for Nexus Media, Inc. She would like to compare the daily travel expenses for the sales staff and the audit staff. She collected the following sample information. Sales (\$) 131 135 146 165 136 142 Audit (\$) 130 102 129 143 149 120 139 At the .10 significance level, can she conclude t

### Hypothesis Test

The management of Discount Furniture, a chain of discount furniture stores in the Northeast, designed an incentive plan for salespeople. To evaluate this innovative plan, 12 salespeople were selected at random, and their weekly incomes before and after the plan were recorded. Salesperson Before After Sid Mahone \$320 \$34

### Hypothesis Testing

Fairfield Homes is developing two parcels near Pigeon Fork, Tennessee. In order to test different advertising approaches, they use different media to reach potential buyers. The mean annual family income for 75 people making inquiries at the first development is \$150,000, with a standard deviation of \$40,000. A corresponding sam

### Hypothesis Testing

A random sample of 15 observations from the first population revealed a sample mean of 350 and a sample standard deviation of 12. A random sample of 17 observations from the second population revealed a sample mean of 342 and a sample standard deviation of 15. At the 0.10 significance level, is there a difference in the populati