Explore BrainMass

Hypothesis Testing

Waiting line model - Queuing Theory

Question 1 Produce trucks arrive at the weigh station at the California border at a rate of 3 per hour according to a Poisson distribution. Livestock trucks arrive at that same weigh station at a rate of 2 per hour according to a Poisson distribution. What is the probability that the number of livestock trucks arriving at the

More variation in the processing time of the new machine

A computer manufacturer is about to unveil a new, faster personal computer. The new machine clearly is faster, but initial tests indicate there is more variation in the processing time. The processing time depends on the particular program being run, the amount of input data, and the amount of output. A sample of 16 computer run

Hypothesis Testing of Mean:IQ scores of Statistics Professor

Null and Alternative hypothesis. For the following claim, find the null and alternative hypotheses, test statistic, P-value, critical value, and draw a conclusion. Assume that a simple random sample has been selected from a normally distributed population. Answer parts a-e. Claim: The mean IQ score of statistics professors

Hypothesis Testing: Independent Sample t Test..

See the attached file for the data. Insurance adjusters are concerned about the high estimates they are receiving from Jocko's Garage. To see if the estimates are unreasonably high, each of 10 damaged cars was taken to Jocko's and to another garage and the estimates recorded. Here are the results: Test the null hypothesi

Conducting a hypothesis test for a population mean

Please help with the following problem. You have a sample size of 120 and the population standard deviation of 20. You are testing the null hypothesis of whether the population mean is 120 or not. A. What are the critical values for rejection when Type I error is 5%? B. If actual mean is 121, find the Type II error C.

Pew Research Automobiles Driving

8.14 Do you enjoy driving your car? The Pew Research Center recently polled n = 1048 U. S. drivers and found that 69% enjoyed driving their automobiles. (a) Construct a 95% confidence interval for the proportion of U. S. drivers who enjoy driving their automobiles. (b) In 1991, a Gallup Poll reported this percent to be 79%


1. Different neighbourhoods may have different crime statistics. A sample of 10 days in Neighbourhood A revealed the following number of crimes per day: 15 12 16 17 15 14 16 10 12 14 A sample of 12 days in Neighbourhood B revealed the following number of crimes per day: 17 13 15 18 16 19 11 21 22 13 16 18 At a 5% l

Statistics: Does ad placement matter?

Does ad placement matter? Corporate advertising tries to enhance the image of the corporation. A study compared two ads from two sources, the Wall Street Journal and the National Enquirer. Subjects were asked to pretend that their company was considering a major investment in Performax, the fictitious sportswear firm in the ads.

Statistics: Analysis of food intake and weight gain

Food intake and weight gain. If we increase our food intake, we generally gain weight. Nutrition scientists can calculate the amount of weight gain that would be associated with a given increase in calories. In one study, 16 nonobese adults, aged 25 to 36 years, were fed 1000 calories per day in excess of the calories needed to

Statistics: Tessler Electric utility, sample of telephone response time

Tessler Electric utility requires service operators to answer the telephone calls from customers in an average time of 0.1 minute or less. A sample of 30 actual operator times are drawn, and the results are given in the following table. In addition, operators are expected to determine customer needs and either respond to them

Professor Pink Panther's test; Dr. Sehr Kurz's summary data

Quiz #4 Professor Pink Panther is a referee (reviewer) for a prestigious international journal, Manuscripta Absurda. Recently, he is giving two articles to review. The following information is for Questions 1 through 5. There are two personality types, Type-A and Type-B. Married couples are made up of three

Statistical Problems for Standard Deviation Distribution

Problem 2b: For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size- (b) 3. Problem 6: For each of the following samples that were given an experimental treatment, test whether these samples represent populations that are different from the general

Forecast: Thiel's U Statistic, ME, MSE, RMSE, MAPE and Forecast Error

See attached Excel data file. For each forecast, set up columns and calculate: Error Squared error Absolute error Absolute % error The numerator of Thiel"s U statistic The denominator of Thiel"s U statistic Calculate ME, MSE, RMSE, MAPE, and U. Questions. 1/ The absolute percentage error for the data point 9/24/

Hypothesis Testing of Mean: Tire Pressure

13.17) An exercise posed the following research question: Many cars have a recommended tire pressure of 32 psi (pounds per square inch). At a roadside vehicle safety checkpoint, officials plan to randomly check select 50 cars for which this is the recommended tire pressure and measure the actual tire pressure in the front left

Statistics M&M project to test proportion of red and brown candies

See attached files. Using the methods in Section 8.4, test the hypothesis (± = 0.05) that the population proportions of red and brown are equal (pred = pbrown). You are testing if their proportions are equal to one another, NOT if they are equal to one another AND equal to 13%. NOTE: These are NOT independent samples, but

Parametric and Non-Parametric Hypothesis Tests

Re-analyze the data in Table 8.18 using nonparametric methods. Assume the samples are unpaired. Table 8.18 Birthweights in a clinical trial to test a drug for preventing low-birthweight deliveries Baby weight (lb) Patient number Treatment Group Control Group 1 6.9 6.4 2 7.6 6.7 3

Test effect of cognitive psychotherapy on positive self-regard

17. A researcher studies the effect of cognitive psychotherapy on positive self-regard. The number of positive statements made about oneself is recorded for each participant during the first meeting. After 8 weekly therapy sessions, the measures are repeated for each person. For the following data. Participant before trea

chart and data analysis of student absences at local middle schools

You will be acting as a community health department investigator who has been hired to look into a mysterious pattern of student absences at some local middle schools in your area. Start here by reading a memo from your boss by clicking on the Memo icon below. This memo outlines the basics of the problem for you. Luckily, yo

Random Sample, Statistical Evidence

1. (a) A random sample of n = 12 E-glass fiber test specimens of a certain type yielded a sample mean interfacial shear yield stress of 34.8 and a sample standard deviation of 4.1. Assuming that interfacial shear yield is normally distributed, compute a 98% C.I. for the true average stress. (Ref: â?? On Interfacial Failure in N

5 Step Hypothesis Test

Assume that a simple random sample is selected from a normally distributed population. Use either the P-value method or the traditional method of testing hypotheses. Listed below are birth weights (in kilometers) of male babies born to mothers on a special vitamin supplement (based on data from the New York State Department

Test hypothesis that hearing is better after a large meal

A researcher theorized that people can hear better when they have just eaten a large meal. 6 individuals were randomly assigned to eat either a large meal or a small meal. After eating the meal, their hearing was tested. The hearing ability scores (high #s indicate greater ability) are given below. Using the.05 level, do the res

Important information about Normal Probability & Hypothesis Testing

Please use Excel and explain which test you use for problem 2 and 3 (t test, ANOVA, two tail or one tail...etc) 1. a. The score on the entrance exam at a well-known, exclusive law school are normally distributed with a mean score of 200 and a standard deviation equal to 50. At what value should the lowest passing score be s

Hypothesis Testing, Test statistic, Z or T test

1) The owner of a local night club has recently surveyed a random sample of n=250 customers of the club. She would now like to determine whether or not the mean age of her customers is over 30. If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. If so, she plan

Statistics 100 - 25 multiple choice

Also see attached file. 1) The owner of a fish market has an assistant who has determined that the weights of catfish are normally distributed, with mean of 3.2 pounds and standard deviation of 0.8 pound. If a sample of 16 fish is taken, what would the standard error of the mean weight equal? 0.003 0.05

Construct hypothesis, random variable, p-value, ANOVA

Statistics Chapter Review Questions For full credit, show all work and it must be clear; final answers must be clear as well. For questions that require a hypothesis test, clearly state H0 , H1,, your conclusion as a sentence, and the reasoning and computations behind your conclusion. Question 3: Eight samples of

Hypotheisis testing problems 37, 41, 43, 53, 55

37.) A study found that in 2005, 12.5% of U.S. workers belonged to unions. Suppose a sample of 400 U.S. workers is collected in 2006 to determine whether union efforts to organize have increased union membership. A.) Formulate the hypotheses that can be used to determine whether union membership increased in 2006 B.) If th

Hypothesis testing using P Value Format

Hypothesis Testing using only P value format. Do not copy and paste all the results from the hypothesis test, you are the expert, only include critical metrics from the test results. Most air traffic passenger use e-tickets. Electronic ticketing allows passengers not worry about paper tickets and it reduces the airlines co

Hypothesis Testing of a Random Sample Size of 64

See the attached file. It is desired to test H0: u=50 against H1: u<50 using alpha=0.1. The population in question is uniformly distributed with standard deviation 20. A random sample of size 64 will be drawn from the population. a) Find beta for each of the following values of the population mean: 49, 47, 45, 43 and 41 b)