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Hypothesis Testing

Statistics: 4 problems

4. Explain why t distribution tends to be flatter and more spread than the normal distribution. 12. Last fall, a sample of n = 36 freshmen was selected to participate in a new 4-hour training program designed to improve study skills. To evaluate the effectiveness of the new program, the sample was compared with the rest of th

Hypothesis Testing, Power of Hypothesis Testing & Cohen's d

2. The value of the z-score in a hypothesis test is influenced by a variety of factors. Assuming that all other variables are held constant, explain how the value of z is influenced by each of the following. a. Increasing the difference between the sample mean and the original population mean. b. Increasing the population

Test the hypothesis: Obtain test statistic & p-value

To test the hypothesis that students who finish an exam first get better grades, Professor Barker kept track of the order in which papers were handed in. The first 25 papers showed a mean score of 77.1 with a standard deviation of 19.6, while the last 24 papers handed in showed a mean score of 69.3 with a standard deviation of 2

Hypothesis & P Value

Hypothesis, Null and Alternative, & P-values Q1: What is a p-value in testing hypothesis? Q2: How does this p-value help us to decide to/not to reject a Null hypothesis? What might happen if we do not use this p-value in particular, when we are rejecting a Null hypothesis? Q3: What are the limits of these p-values t

Hypothesis: Null and Alternative

1: How do you decide your null and alternative hypotheses? 2: How do you as a researcher decide the confidence level? What factors do you consider to make that decision? 3: How do you decide on the type of test? For example, should you use z-test, t-test, or non-parametric test that we will study later on [such as x^2 test, F-

Confidence interval for mating behavior of the Mormon cricket

In a field study of mating behaviour in the Mormon cricket, a biologist noted that some females mated successfully while others were rejected by the males before coupling was complete. The question arose whether some aspect of body size might play a role in mating success. The accompanying table summarizes measurements of head

Hypothesis Test in a Maternity Ward

The duration of human gestation is on average 40.5 weeks. In a maternity ward, we note the gestational age of 100 consecutive newborns. The sum of these ages is equal to 3850 weeks and the standard deviation is 5 weeks. We believe that it is a ward for premature births. Do we have enough evidence to support our claim? Make su

I need to know how you got the answer

Suppose that the sales manager of a large automotive parts distributor wants to estimate as early as April the total annual sales of a region. On the basis of regional sales, the total sales for the company can also be estimated. If, based on past experience, it is found that the April estimates of annual sales are reasonably ac

Hypothesis Test

Here are heart rates for a sample of 30 students before and after a class break. At alpha = .05, was there a significant difference in the mean heart rate? (a) State the hypotheses. (b) State the decision rule and sketch it. (c) Find the test statistic. (d) Make a decision. (e) Estimate the p-value and interpret it. Heart

Test for significant differences among 3 treatments

For the preceding problem you should find that there are significant differences among 3 treatments. The primary reason for the significance is that the mean for treatment 1 is substantially smaller than the means for the other two treatments.To create the following data we started with the values from problem 7 and added 3 poin

Evaluate the effect of a treatment in population with a mean

To evaluate the effect of a treatment , a sample of n=9 is obtained from a population with a mean of m=40 and the treatment is administered to the individuals is found to be M-33 A: If a sample has a standard deviation of s=9, are the data sufficient to conclude that the treatment has a significant effect using a two tailed t

Sample Data Association for Remodeling Projects

The association of Home Builders provided information on the cost of the most popular home remodeling projects. Sample data on cost for the two types of remodeling projects are as follows.(in thousands of dollars) Kitchen Master Bedroom 25.2 18 17.4 22.9 22.8

Significant Difference

Here are heart rates for a sample of 30 students before and after a class break. At ? = .05, was there a significant difference in the mean heart rate? (a) State the hypotheses. (b) State the decision rule and sketch it. (c) Find the test statistic. (d) Make a decision. (e) Estimate the p-value and interpret it. HeartRate

Set up hypothesis with a 2-tailed decision rule

A half-liter bottle of soft drink is supposed to contain a mean of 520 ml. The filling process follows a normal distribution with a known process standard deviation of 4 ml. (a) Which sampling distribution would you use if random samples of 10 bottles are to be weighed? Why? (b) Set up hypotheses and a two-tailed decisi

Measuring Association of age group v where people get their news

See attached file. Measuring Association Go to the Resources section in this syllabus and open the file media.xls. This file contains information from a study indicating where different age groups primarily get their news. Each cell represents the number of responses from that particular group. At the .05 level of sig

Waiting time of body shops in Bangor, Maine

Problem 1 There are four auto body shops in Bangor, Maine, and all claim to promptly serve customers. To check if there is any difference in service, customers are randomly selected from each repair shop and their waiting times in days are recorded. The output from a statistical software package is: ANOVA Source of Varia

Single mean, one-tailed; single populations proportion, two-tailed

Need a brief example of the following: Cite an example of how you could/would apply a test of a hypothesis for a single mean, one tail test described in the lecture to real world situations? Make sure you state your hypothesis in both the null and alternate form as well as showing the hypotheses in symbol form such as Ho : u

Hypothesis Testing of Unit Production

1. An industrial engineer at Lyons Products would like to determine whether there are more units produced on the afternoon shift than on the morning shift. A sample of 50 morning-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 showed the

Abolition of the death penalty in 12 nations Crime rate change

There has been much debate over the use of the death penalty. Advocates of the death penalty feel that the penalty will reduce crime. However, as we have seen in recent years, it is being revealed that many innocent individuals may have been falsely convicted and sentenced to death due to prejudiced jurors and mishandling of evi

Probability Plot, Sample Size, ANOVA, & Regression

1. What are the four levels of measurement scales? Give examples of each and explain in detail. 2. Explain the use of normal probability plot to evaluate whether a set of data is normally distributed? Please discuss in detail. 3. Discuss how a sample size, n, an increase in confidence is achieved by widening the confidenc

Null and alternative hypothesis for t-test, state the decision

Question #1- Using your experience from previous or current employment, provide a business example where you could use a t-test to assist in a business decision. State the null and alternative hypothesis. The null and alternative should be the exact opposite of each other and the t-test will be looking for a difference between t

Statistics: Caffeine consumption of a sample of 49 adult women

A summary on the daily consumption of caffeine for a sample size of 49 adult women produced: Ð? = 49 X bar = 215 mg s = 235 mg range: 5 to 1176 1. Does it appear plausible that the population distribution of daily caffeine consumption is normal? Explain 2. Is it necessary to assume a normal population distribut

Differences between urban and suburban restaurants for variables

See attached data file. Assignment 6 Measuring Differences Between Two Means (1) Go to the Resources section in this syllabus and open the file restaurants.xls. This data file contains ratings for food, decor, service, and the price per person for a sample of 50 restaurants located in an urban area and 50 restaurants

Statistics on Human Body Temperture

Human Body Temperature: What's Normal? In an article in the Journal of Statistics Education (vol. 4, no. 2, 1996), Allen Shoemaker describes a study that was reported in the Journal of the American Medical Association.* It is generally accepted that the mean body temperature of adult humans is 98.6°F. In his article, Shoemaker

Statistics Problems 23, 27, 11, 13, 17 and 25

Problems 23 & 37 For each claim, assume the distribution of the population is approximately normal. 23. Microwave Repair Costs ◆ A microwave oven repairer says that the mean repair cost for damaged microwave ovens is less than $100.You work for the repairer and want to test this claim. You find that a random sample

Article Analysis: Job satisfaction of managers in tourism in Turkey

Prepare an analysis of your selected article. Start by identifying and summarizing the hypothesis described in the article. Then explain whether the hypothesis was rejected or accepted, and what the implications of this finding are for the study. Use the following article: Job satisfaction of managers in tourism: Cases in the