Share
Explore BrainMass

Hypothesis Testing

positive critical value of a test

A random sample of 145 recent donations at a certain blood bank reveals that 74 were type A blood. Does this suggest that the actual percentage of type A donors differs from 40%, the percentage of the population having type A blood? Carry out a test of the appropriate hypotheses using a significance level of 0.01. Let p re

Probability Problems

#3 - Use your own paper as an answer sheet. Show all mathematical calculations. No partial credit will be given if work is not shown. A calculator will be required to complete the exam. 1. Find the 90% confidence interval for a population mean if the sample mean is 21.6 with a standard deviation of 2.8 for a sample of 35.

Business Plan - Statistics Section

A. Clearly define the dependent and independent variables that are the focus of the team's study. The dependent variable is the variable whose value is the result or is a function of the control or independent variables. b. State the null and alternative hypotheses and the theories that support these hypotheses that will be t

Hypothesis Testing Question

3. The director of admissions at the University of China is concerned about the high cost of textbooks for the students each semester. A sample of 20 students enrolled in the university indicates that X (bar) = $316.4 and s = $43.20. Answer the following questions in detail by using Excel.

Step-wise answer to Testing of hypothesis problems

A decade-old study found that the proportion, p, of high school seniors who believed that "getting rich" was an important personal goal was 75%. A researcher decides to test whether or not that percentage still stands. He finds that, among the 250 high school seniors in his random sample, 182 believe that "getting rich" is an im

What does it mean to decrease the level of significance?

If we decrease the level of significance a (alpha) from 0.05 to 0.01, that means we are: A. More willing to accept a type II error; B. More willing to accept a type I error; C. Less willing to accept a type I error; D. None of the above.

Testing of Hypothesis with a Student T Test

See attached file for full problem description. 15. Injuries to Major League Baseball players have been increasing in recent years. For the period 1992 to 2001, league expansion caused Major League Baseball rosters to increase by 15%. However, the number of players being put on the disabled list due to injury increased 32%

ANOVA Calculation: Research Summary

1. Choose one article (link provided below) to examine and work through as an ANOVA calculation. In this regard, remember the goal will be to work through an ANOVA test to compare the means of three or more groups of data. If the article your group selected does not have enough data to complete an ANOVA calculation, please feel

Z statistic and the critical value: one-tailed test of hypothesis

1) An automobile assembly line operation has a scheduled mean completion time, mean, of 12.8 minutes. The standard deviation of completion times is 1.2 minutes. It is claimed that, under new management, the mean completion time has decreased. To test this claim, a random sample of 44 completion times under new management was tak

Test of hypothesis-Z statistic and p-value

A manufacturer claims that the mean lifetime, mean, of its light bulbs is 52 months. The standard deviation of these lifetimes is 7 months. Ninety bulbs are selected at random, and their mean lifetime is found to be 55 months. Can we conclude, at the 0.05 level of significance, that the mean lifetime of light bulbs made by this

Is there difference in the balance time across the practice groups?

A short study was conducted to determine if balance could be improved with practice technique. After obtaining the length of time (in minutes) a subject can balance on 1 leg on a 12 inch wooden block, subjects were randomly allocated to 4 practice groups. Each group was taught different technique to improve balance. Subjects wer

T test

To investigate the efficacy of a diet, a random sample of 16 male patients is drawn from a population of adult males using the diet. The weight of each individual in the sample is taken at the start of the diet and at a medical follow up 4 weeks later. Assuming that the population of differences in weight before versus after the

Using the Five-Step Hypothesis Testing

Use the five-step hypothesis testing procedure to solve the following exercises. 21. 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

AIU - Testing of Hypothesis (Job Satisfaction)

Using AIU's large database of survey responses from the AIU data set, complete the following: Perform hypothesis testing on one variable's data. (Choose either the intrinsic or extrinsic column.) Perform a t-test by formulating a null and an alternative statement, choosing an acceptable significance value, selecting the test s

Statistics matching question: definitions/examples of statistical terms

The mean number of college credits earned in the fall by students at City University is to be estimated by determining the mean number of credits earned in the fall semester by the 100 students enrolled in statistics 202. Data (one piece of) Data (set of) Experiment Parameter Population Sample Statistic Variable A

Hypothesis Testing - Real Life Example

Make a decision regarding the null hypothesis based on the sample information and interpret the results of the test, state whether we proved or disproved the null hypothesis and why the data proves this. A company needs to purchase company cars for their sales staff. They contacted their local Ford dealership and inquired as

Statistical Difference Formula for Microsoft Access

I am looking to design something in Microsoft Access, but not sure how to do the two statistical calculations. For example, assume there are two columns of data labeled January and February. In each of these columns are the numbers 0-4. Where 0=Blank Response, 1=Poor, 2=Fair, 3=Good, 4=Excellent I want to know if th

Hypothesis test for the difference of population means: Paired comparisons

Attached is 2 slides on powerpoint. The 1st slide is the problem and the 2nd slide is the answer format. Answer 3 is completed because it requires the use of a t test with degree of freedom that equals 11. Attached also is the excel data Please help with 1,2,4,5 and 6 only 1) eg: u=0 or u>0 etc 2) same as 1 3) answere

Hypothesis Testing in Hockey Players

How tall are college hockey players? The average height has been 68.3 inches. A random sample of 14 hockey players gave a mean height of 69.1 inches. We may assume that x has a normal distribution with mu = 0.9 inch. Does this indicate that the population mean height is different from 68.3 inches? Use 5% level of significan

Can you write this as an equation?

The hypothesis is that the Southerners are less educated than the population at large. Now keep in mind that because this is a one tailed test, you can interchange the null and the alternate hypothesis. Also, null is usually given the benefit of the doubt. Thus the '=' sign goes with the null. In this case because we have to pro

Students t test for GPA score in SPSS

Time to complete complex math problems while listening to music was investigated using 16 high school students. Students were matched on their math gpa, then randomly assigned to either the Country Western music group or the Classical music group. a. Conduct the appropriate analysis to determine if there was an effect of t

P-Value of Quality Inspectors Test

Test of product quality using human inspectors can lead to serious inspection error problems. To evaluate the performance of inspectors in a new company, a quality manager had a sample of 12 novice inspectors evaluate 200 finished products. The same 200 items were evaluated by 12 experienced inspectors. The quality of each item

Specify the appropriate hypothesis for testing

2) Researchers at the University of South Alabama compared the attitudes of male college students toward their fathers with their attitudes toward their mothers. Each of a sample of 13 males was asked to complete the following statement about of their parents: My relationship with my father (mother) can best be described as: (1

Critical analysis of a research article

1. Analyze data analysis to determine whether the appropriate statistical procedure were used to analyze data. 2. Provide an explanation of the meaning of the results of each study based upon the findings from the statistical tests. Article attached -- it's about differences in health care in people before and after they

Null Hypothesis and Statistical procedures for wing to rotary wings aircraft data. Null Hypothesis, Alternative Hypothesis, Significance Level, Critical Value, P value are included in the solution.

Null Hypothesis and Statistical procedures. 1. You are in charge of the training program for pilots transitioning from fixed wing to rotary wings aircraft. You are considering the purchase of a simulator for initial training, but you are unsure if the quality of the simulator training will be worth the expenditure. You have a