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Hypothesis Testing

Significance Level Dependent Variables

1. A researcher collected data from 28 individuals. Seven independent variables were used to predict a dependent variable. The value of R2 for this model was .87. When the variable X_1 and X_3 were omitted from the model, R^2 was .84. Do the variables X1 and X3 contribute to the prediction of the dependent variable? Use a .10 si

Conclude is Performance is Independent of Time of Shift

Suppose that the medical staff indicates that the results of a given laboratory procedure must be available 30 minutes after the physician submits a request for the service. In this situation, if the results arrived 30 minutes or less after the request, we regard the performance of the laboratory as timely. If results arrived mo

Statistics: computerized tutorial center

A computerized tutorial center at a local college wants to compare two different statistical software programs. Students going to the center are matched with other student having similar abilities in statistics (assume the matching process creates matched pairs acceptable for use with the appropriate paired test statistic for t

Critical Thinking Statistical Analysis of an Article

Critical Thinking Concept Review 1. Choose three peer C-reviewed research articles and write a short review of each of them that includes the following: a. Write the problem statement. b. Name the theoretical model used or briefly describe the overall conceptual model. c. Write out the main research questions. What is the ra

HYPOTHESIS TESTING: Null Hypothesis Relative to Problem and Decision.

In your environment (business or personal), please describe a hypothesis test related to a decision. What would be your data? What would be your null hypothesis? What would be your alternate hypothesis? What would be your Type 1 and Type 2 errors relative to your decision? Suppose you have a p-value of 0.01, what does this mean

Hypothesis Tests Related to Real Life Decisions

In your environment (business or personal), please describe a hypothesis test related to a decision. What would be your data? What would be your null hypothesis? What would be your alternate hypothesis? What would be your Type 1 and Type 2 errors relative to your decision? Suppose you have a p-value of 0.01, what does this mean

Determining Level of Significance for Proportion of Sample Who Enjoy Shopping

Sample question: A sample of 500 shoppers were selected in a large metropolitan to determine various information concerning consumer behavior. Among the questions asked was, "Do you enjoy shopping for clothing?" The results are summarized in the following contigency table: Enjoy Shopping for Clothing MALE FEMALE TOTAL Y

Creating a hypothesis for an experiment

How do you set up hypotheses for the following situations: a. Jill is interested in comparing academic preparedness of high school seniors in Utah. She thinks that the ACT is a good measure of how prepared these students are for college and she wants to know if boys are more prepared than girls for success in college. b

Hypothesis testing and significance test for hypoglycaemia

Rachel's doctor suspects she is suffering from hypoglycaemia. The amount of glucose in the bloodstream varies and a person with hypoglycaemia has an average blood glucose level of less than 65 mg/dL. To determine whether Rachel is indeed hypoglycaemic the doctor sends her home with a glucose monitor to test her blood at 40 rando

Mean weight of whole from sample size

I do not know how to do the following question: "A fish wholesaler has a catch of several thousand lobsters. A prospective buyer selected 40 at random and obtained the following weights in ounces: 21.3, 21.1, 21.4, 18.8, 20.2, 19.3, 19.1, 18.3, 19.9, 22.0, 20.6, 20.7, 21.9, 20.1, 17.1, 19.3, 21.2, 18.4, 21.0, 21.6, 16.5,

Mean amount of force necessary

The quality control engineer for a furniture manufacturer is interested in the mean amount of force necessary to produce cracks in stressed oak furniture. She performs a twotail test of the null hypothesis that the mean for the stressed oak furniture is 650. The calculated value of the Z test statistic is a positive number that

Scientific Method in Practice

#2 Choose a research article from your field. Write the five hypotheses that this study is testing. Write both the null and alternative hypotheses for each one. #3 Imagine that you are going to conduct a study. Write the purpose of the study, research questions, and main hypotheses. Write both the null and alternative hypothe

Production process of average weight

1. The task of all hypothesis testing is to ____ H0 or ____ H0. Answer reject, fail to reject reject, fail to accept accept, fail to accept fail to reject, discredit accept, reject 12.When testing H0: m =m0 versus Ha: m ≠ m0, if H0 is rejected then the conclusion is: Answer Based on the sample data, there

Difference in variability and P value

Sample Question: A bank a branch location a commercial district we city developed improved process serving customers noon-to 1 pm. lunch period. the waiting time (defined as the time elapsed from when the customer enters the line until he or she reaches the teller window) needs to be shortened to increase customer satisfaction.

Difference between two groups concerning age, children & education

Please see the attached MS Word document for the comparison charts. Investigate whether there is a significant difference between these two groups in terms of their age, number of children, and education. Assume that x is .05 for a two-tailed test. Based on your analysis, write three 5-type statements summarizing your findin

Inequalities in annual salary for employees with similar ratings

The personnel director for a local manufacturing firm has received complaints from the employees in a certain shop regarding what they perceive to be inequities in the annual salary for employees who have similar performance ratings, years of service, and relevant certifications. The personnel director believes that an employee

Levels of significance questions

Many times researchers preselect the value of alpha of .01 or .001. What are the factors that allow selection of either of those levels of significance? When computing Independent Sample Test, the SPSS output contains the section stating that Confidence Interval of the Difference. What is a Confidence Interval and what is t

Statistical Hypothesis Testing

1. State the null and alternative hypothesis for the following situations. a) A federal auditor believes that a health care company has overcharged its patients. b) The editor of a magazine believes that the mean income of subscribers to its magazine is $75,000. c) An operations manager must maintain machines that produce 50

Transition pressure of bismuth as a function of temperature

Question 1 An experiment was conducted to investigate the transition pressure of bismuth as a function of temperature. Listed below in Table 3.1 are the temperature (x) in degrees Centigrade and the difference in pressure (y) from 25,000 bars in hundreds of bars for 23 samples. (So if y = 3.66 then the pressure is 25, 000 + 3

Hypothesis Testing: Unemployment Levels

Federal administration stated that unemployment level in US is 8.6% (population proportion = 0.086). A hypothesis test is to be performed to decide whether unemployment level in NY State differs from national level. a) formulate the null hypothesis b) formulate the alternative hypothesis c) classify the hypothesis test as two-t

Did the two samples come from the same population: F max test

The following data are from two separate samples. Does it appear that these two samples came from the same population or from two different populations? Use an F max test to determine whether there is evidence for a significant difference between the two population variances. Use the 0.05 level of significance. Use an indepe

Two-Tailed Test: Development of Social Skills

A psychologist is examining the influence of an older sibling in the development of social skills. A sample of 24 three year old children is obtained. Half of these children had no siblings and the others had at least one older sibling who is within 5 years of the child's age. The psychologist records a social skills score for e

Cold Medication Effect on Mental Alertness

A researcher would like to determine whether an over-the-counter cold medication has an effect on mental alertness. A sample of n = 16 participants is obtained and each person is given a standard dose of the medication one hour before being tested in a driving simulation task. for the general population reaction time scores on t

Children with ADHD and TV

Recent results suggest that children with ADHD also tend to watch more TV than children who are not diagnosed with the disorder. Tto examine this relationship a researcher obtains a random sample of n=36 children 8 to 12 years old who have been diagnosed with ADHD. Each child is asked to keep a journal recording how much time is

Bottled water study

4.44) A four year study of bottled water brands conducted by the natural resources defense council found that 25% of bottled water is just tap water packaged in a bottle. Consider a sample of five bottled water brands and let x equal the number of these brands that use tap water. a. explain why x is a binomial random variable

Fortune 500 CEO Salaries

The Stocks included in the S & P 500 are those of large publicly held companies that trade on either the New York Stock Exchange or the NASDAQ. In 2008, the S&P 500 was down 38.5%, but what about financial compensation (salary, bonuses, stock options, etc.) to the 500 CEOs that run the companies? To learn more about the mean CEO

Hypothesis Testing: American Male Height

According to the U.S National Center for Health Statistics, the mean height for adult American males is mu = 65.5 inches. Assume the heights are normally distributed with standard deviation of sigma = 3.2. You may use StatCrunch for showing work, showing sketches and making calculations Determine the probability of finding an

Century National Bank

Century National Bank Refer to the Century National Bank data (attached). Is it reasonable that the distribution of checking account balances approximates a normal probability distribution? Determine the mean and the standard deviation for the sample of 60 customers. Compare the actual distribution with the theoretical di