Share
Explore BrainMass

Hypothesis Testing

Customers were waiting in line too long so data was collected. The mean time was 28 minutes. One month later a sample of 127 customers was selected. The mean wait time recorded was 26.9 minutes and the S.D. of the sampling was 8 minutes. Using the .02 level of significance, conduct a 5 step hypothesis testing to determine if the new processes significantly reduced the wait time.

Customers were waiting in line too long so data was collected. The mean time was 28 minutes. One month later a sample of 127 customers was selected. The mean wait time recorded was 26.9 minutes and the S.D. of the sampling was 8 minutes. Using the .02 level of significance, conduct a 5 step hypothesis testing to determine if th

Mean and Standard Deviation of Allowance in Tennessee

A nine year old gets 3.65 for allowance. Sample of 45 9 year olds in Tennessee revealed mean allowance 3.69 with a standard dev. of .24 . At .05 significance is there a difference mean allowance in Alabama for 9 year olds.

Five Step Hypothesis Testing

A salesman makes 40 calls per week. People complained because they said that estimate was to low. In a random sample of 28 people, the standard deviation was computed to be 2.1 calls at the the significant level .05. Can one conclude that more than 40 calls were made on average?

Estimating the P-Value of a Sample

Experience raising New Jersey red chickens revealed the mean weight of the chickens at five months is 4.35 pounds. The weights follow the normal distribution. In an effort to increase their weight, a special additive is added to the chicken feed. The subsequent weights of a sample of five-month old chickens were (in pounds):

Identify the null hypothesis and testing significance

Test the given claim. Identify the null hypothesis, alternative hypothesis, and test statistic, P-value or critical value(s). Provide a conclusion about the null hypothesis, and a final conclusion that addresses the original claim. Use the P-value method unless your instructor specifies otherwise. Travel Through the Internet

Hypothesis Tests of Equal Variances

Test the given claim. Use a significance level of a = 0.05 and assume that all populations are normally distributed. 11. Hypothesis Test for Magnet Treatment of Pain. Researchers conducted a study to determine whether magnets are effective in treating back pain, with results given below (based on data from "bipolar Permane

Test the claim

You are given the following data. Test the claim that there is a difference in the means of the two groups. Use alpha = 0.10. Group A Group B

Hypothesis testing and sample size

Please see attached. A sample of size n = 14 is selected from a normal population to construct a 95% confidence interval estimate for a population mean. The interval was computed to be (7.82 to 9.64). Determine the sample standard deviation. (4 pts) Determine the p-value for each of the following hypothesis-testing situat

Normal Distributions, Central Limit Theorem and Age Distribution

Questions: Work each question, using Excel where appropriate. Remember, each gestation period is its own normal distribution. Thus, you will need to change the "mean" and "standard deviation" to reflect the question you are answering. 2. What percent of the babies born with each gestation period have a low birth w

Finding the Effectiveness of Teaching Methods

Six groups of randomly selected students matched for IQ and age were formed. Each student was taught a concept of time by using one of three methods: Lecture, demonstration, or teaching machine. The scores are shown in the table below indicated the student's performance when they were tested on how well the grasped the concept.

School Committee members of a midsized New England city

Exe_1Wk1.xls The School Committee members of a midsized New England city agreed that a strict discipline code has caused an increase in the number of student suspensions. The number of suspensions for September 1992 - February 1993 for a sample of the schools is provided below. {Data} The average num

Comparing the mean size

Suppose that you want to compare the mean size of health care claims submitted by five groups of policyholders. Ten claims are randomly selected from amongst the existing claims for each of the five groups. The data is shown in the following table: Group 1 ($) Group 2 ($) Group 3 ($) Group 4 ($) Group 5 ($) 763 1,3

Statistical Strategy and Quantitative Perspectives

I have been asked to suppose that faculty at my college are assigned overload courses hence additional compensation beyond the required contract hours based on seniority. There is a concern that new faculty may not be able to enjoy the same financial compensation as their senior faculty counterparts. How would you, from a quanti

Stonefield Homes is developing 2 parcels near Minneapolis, MN.

Stonefield Homes is developing 2 parcels near Minneapolis, MN. In order to test different advertising approached, they use different media to reach potential buyers. The mean annual family income for 75 people making inquiries at the first development is $150,000, with a standard deviation of $40,000. A corresponding sample of 1

Stating Null and Alternative Hypothesis

Help with Stating Null and Alternative hypothesis and the theories that support these hypotheses: Lemarks Studios is looking for advertiser dollars to help with production costs on its newest blockbuster movie. Lemarks Studios has several companies that want product placement in the film. The films producers wonder how many t

Statistical Tests: Define the Population

Choose a variable. Before collecting the data, decide what a likely average might be, then complete the following: Write a brief statement of purpose of the study Define the population State the hypotheses for the study Select an a value State how the sample was selected Show the raw data Decide which statistical t

Single Mean & Difference Between Two Means & Standard Deviation

Explain the difference between testing a single mean and testing the difference between two means. What two assumptions must be met when one is using z test to test differences between two means? When can the sample standard deviations s 1 and s 2 be used in place of the population standard deviations s 1 and s 2?

Hypothesis Testing, Z-Tests and T-Tests

A. Select a variable. Compare the mean of the variable for a sample of 30 for one group with the mean of the variable for a sample of 30 for a second group. Use a z test. B. Select a variable. Compare the mean of the variable for a sample of 10 for one group with the mean of the variable for a sample of 10 for a second group

Hypothesis Testing and Variation in Data

TRUE OR FALSE? (WITH JUSTIFICATION) 1. Supporting the null hypothesis would be possible only if we could prove it for 100% of all possible cases. 2. If the claim says that µ >200 and the sample mean is 215, we can say that the claim is true because it is obvious even without a formal test. 3. A Calculated Value of

Assessing variability in a dataset

1. Variability in a dataset may be caused by various sources. Provide an example sample dataset where one or more than one sources causing its variability. Explain briefly with one or two lines explanations of those sources. Also, calculate the sample variance for the example data set that you have provided. 2. Organize the

Hypothesis Testing and Decision Rules

An auditor reviewed 25 oral surgery insurance claims from a particular surgical office determining that the mean out-of-pocket patient billing above the reimbursed amount was $275.66 with a standard deviation of $78.11. a. At the 5 percent level of significance, does this sample prove a violation of the guideline that the ave

Coin Flips and Hypothesis Testing

A coin was flipped 60 times and came up heads 38 times. a. At the .10 level of significance, is the coin biased towards heads? Show your decision rule and calculations. b. Calculate a p-value and interpret it.

Type I and Type II error..

Type I and Type 11 error Please see attached. Thank you. Describe the action that would result in a type I error and a type II error if each of the following null hypotheses were tested. a. H0: There is no waste in US Defense Department spending b. H0: This fast-food menu is not low fat