Please explain in your own words: 1. Define the null hypothesis. If the null hypothesis is rejected then? 2. The level of significance is the? 3. Type II error is committed when? 4. The level of significance in hypothesis testing is the probability of? Please explain and show all calculations. 5. If n=16, me
Lets say a business has account receivables per customer of $60.54. There was a random sampling of 19 accounts that revealed a sample mean of $73.55 and a sample standard deviation of $19.29. To compute the null hypothesis, I would have to test to see if $60.54 (null hypothesis) has changed. Is this correct?
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
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-
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
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
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
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
Who decides what the confidence level in a hypothesis test should be and based on what factors?
Conduct a test of the hypothesis that the mean price of the stocks on Sample "A is the same as the mean price of all of the stocks in Sample"B". Show all five steps and discuss in detail the implications of the results of this hypothesis test. see attachment for samples
8) For the data in the matrix No Treatment Treatments Male M-5 M-3 overall M-4 Female M-9 M-13 overall M-11 overall M-7
16) The structure of two-factor study can be presented as a matrix with the levels of one factor determining the rows and the levels of a second factor determining the columns. With this structure in mind, describe the mean differences that are elevated by each of the three hypothesis tests that make up a two factor ANOVA
For the preceding problem you should find that there are significant differences among the three treatments. One reason for the significance is that the sample variances are small. To create the following data, we started with the values from problem 9 and increased the varibility (the Ssvalue) within each sample. 1
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
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
10) 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 tail
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
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
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
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
See attached data file. Measuring Differences Among Three or More Means Modern software applications require rapid data access capabilities. An experiment was conducted to test the effect of data file size on the ability to access the files (as measured by read time, in milliseconds). Three different levels of data file si
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
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
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
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
In the belief that Statistics is too hard, a student claims that the mean score on a final exam is less then 70. 15 scores will be chosen at random to test this claim. Assume that scores on statistics tests are approximately normally distributed. Express the claim in symbolic form. State the null and alternative hypothesis for t
A study was carried out and subjects were randomized to 2 groups: Group A: control diet group, N=154 Group B: a fruit-and-vegetable group, N=154. The 97.5% CI for mean changes in Group B minus mean change in Group A is (-4.7 to -0.9). Suppose we want to compute a two-sided p-value to compare the two groups. Without doing
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
A college class believes that the average grade average of psychology students and the average grade averages of biology students are different. The class found that the actual grade averages of a sample of 8 psychology students was 3.5 and the average grade average of a sample of 11 biology students was 3.2. What is the null hy
See attached file. Measuring Differences Between Two Means Over the past year, the Vice President of Human Resources at a large medical center has run a series of three-month workshops aimed at increasing worker motivation and performance. To check the effectiveness of the workshops, she selected a random sample of 35 emp