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# Hypothesis Testing

### Construct a 95% confidence interval estimate of the difference between the percentage of men and the percentage of women who fear flying.

The lives of many people are affected by a fear that prevents them from flying. An institute for public opinion conducted a poll of 1014 adults, 48%of whom were men. The results reported in USAToday showed 12 % of the men and 33% of the women fear flying. 1. Construct a 95% confidence interval estimate of the difference betw

### P-Value & Test

Question 1: The Survey of Study Habits and Attitudes (SSHA) is a psychological test that measures the motivation, attitude, and study habits of college students. Scores range from 0 to 200 and follow (approximately) a normal distribution with mean 115 and standard deviation 25. You suspect that incoming freshmen have a mean u

### Two tailed Hypothesis test using z-statistics

Question: To test whether or not there is a difference between the mean grade point average of male math majors and female math majors at a certain university, 2 random samples were gathered. For the 35 males, we find that x1= 3.1 with s1=0.2. For the females, x2=3.2 with s2=0.15. Test at a level of significance of 1%.

### 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%.

### Based on the regression results, give an estimated adjusted hazard ratio. What does 95% power mean? Which of the following conclusions is most likely?

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

### Statistics

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

### 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.

### Statistics Problems

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,

### 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: The statement that the probability of a Type I error is 0.05 means? Which of the following interpretations of the 95% confidence interval is correct?

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

### 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

### 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

### Testing of population proportion.

Identify the null hypothesis , alternative hypothesis, test statistic, p-value or critical value(s), conclusion about the null hypothesis, and final conclusion that addresses the original claim. Travel Through the Internet - Among 734 randomly selected internet users, it was found that 360 of them use the internet for makin

### Testing the heights of baseball bounces

In previous tests, baseballs were dropped 24ft onto a concrete surface, and they bounced an average of 92.84% in. In a test of a sample of 40 new balls, the bounce had a mean of 92.67 in. and a standard deviation of 1.79 in. Use a 0.05 significance level to determine whether there is sufficient evidence to support the clam tha

### Finding Significant Difference and P-Value

More shoppers do their majority of grocery shopping on Saturday than any other day of the week. However, is the day of the week a person does the majority of grocery shopping dependent on age? A study cross-classified grocery shoppers by age and major shopping day ("Major Shopping by Day ," Progressive Grocer Annual Report, Ap

### Is Friday the 13th any more unlucky than Friday the 6th? Do a hypothesis test to find out.

A data set can be found at the Data and Story Library site: http://lib.stat.cmu.edu/DASL by searching for Friday the 13th materials. The data were collected in an effort to study various aspects of human behavior on Friday 13th by monitoring the change in traffic patterns between Friday the 6th and the subsequent Friday the 1

### Comparison Involving Means - Provide descriptive statistical summaries of the date for each model

Par, Inc., is a major manufacturer of golf equipment. Management believes that Par's market share could be increased with the introduction of a cut-resistant, longer-lasting golf ball. Therefore, the research group at Par has been investigating a new golf ball coating designed to resist cuts and provide a more durable ball. T

### Testing of population proportion based on Z test

In some places in the US, people are aware of the need for more care for older citizens, like Dr. Hope. In the election in one area, they put forward a referendum that would increase the county sales tax by one cent to pay for increased services for this important part of the community. Registered voters were asked to vote Yes,

### Hypothesis Testing and Measurements in Research

Some feminists have asserted that the Wechsler IQ tends to treat females differently from males. Another group, who advocates for people with psychiatric disorders, might say the same thing about people with psychiatric disorders. To examine these alleged differences they studied the following clients using only the most indicat

### Hypothesis Testing and Statistical Measurements

You have been fortunate enough to receive a grant from a foundation studying pain in arthritis victims under the age of 30. You have not found a lot of people, but you think that you may have identified something that works pretty good. They are measured on an established scale pain scale from 20 (not much pain) to 100 (a lot of