Share
Explore BrainMass

Hypothesis Testing

Hypothesis Test for Measuring Male Egyptian Skulls

The values in the table are measured maximum breaths of male Egyptian skulls from time periods. Changing in head shape over time suggest that interbreading occurred with immigrant populations. Use a 0.05 level significance to test the claim that the different time periods do not all have the same mean. 4000BC 1850BC

Quantifiable Statistics

The thing about selling all of those drugs, devices, and solutions is that a lot can go wrong. Nearly every product that Baxter delivers is a matter of life and death. But when the outcome is death, it can be incredibly difficult to determine a treatment's effectiveness. Was the death normal and predictable? Or did the treatment

Proportion testing using Z test

Workers Bosses N1=436 N2=121 X1=192 X2=40 Assume that you plan to use a significance level of a=.05 to test the claim that P1 = P2. Use the given sample sizes in numbers of success to find p -value.

Hypothesis Testing - A presidential candidate's aide estimates that, among all collge students, the proportion p who intend to vote in the upcoming election is at most 65%. If 190 out of a random sample of 260 collge students expressed an intent to vote, can the aide's estimate be rejected at the 0.05 level of significance? ...

A presidential candidate's aide estimates that, among all collge students, the proportion p who intend to vote in the upcoming election is at most 65%. If 190 out of a random sample of 260 collge students expressed an intent to vote, can the aide's estimate be rejected at the 0.05 level of significance? Perform a one-tailed

Hypothesis Testing - A coin-operated drink machine was designed to discharge a mean of 8 ounces of coffee per cup. Suppose that we want to carry out a hypothesis test to see if the true mean discharge differs from 8. State the null hypothesis and the alternative hypothesis that we would use for this test. ...

A coin-operated drink machine was designed to discharge a mean of 8 ounces of coffee per cup. Suppose that we want to carry out a hypothesis test to see if the true mean discharge differs from 8. State the null hypothesis and the alternative hypothesis that we would use for this test. Ho: ________________________ H1: ___

SSE's, SST's, F-ratio, ANOVA, and null hypothesis

Problem 1 An aircraft manufacturer is attempting to determine if the average leg length of the adult male has changed from 44". A sample of 81 men was selected randomly and the average length was found to be 45.5", with a standard deviation of 5.5". Test the null hypothesis that the average leg length of the adult male is 44"

Statistics - Hypothesis Testing Non-Sales Items

To measure the effect of a storewide sales campaign on non-sale items, the research director took a random sample of 13 pairs of stores that were matched according to average weekly sales volume. One store of each pair (the experimental group) was exposed to the sales campaign, and the other member of the pair (the control) gro

Inference about Population Proportion

Part I:  In this exericse, we have a box of paint cans for a project kit.  The box contains 100 bottles in total, with the following colors:   yellow,  black,  green,  blue.   We will randomly select 15 bottles from the box and count how many are yellow.     

Statistical questions: Chi-square, two-tailed hypothesis, optimum sample size

1. Since we have determined the optimal sample size, n, using a three variable formula. Fill in the following table listing the three variables and specify the effect on n (either + or -) of increasing and decreasing each variable, one at a time. VARIABLE EFFECT of INCREASE EFFECT of DECREASE 2. Given a Chi-Squar

Rejection Region For A Hypothesis Test

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 she wants to be

Hypothesis Testing

Microsoft Excel was used on a set of data involving the number of parasites found on 46 Monarch butterflies captured in Pismo Beach State Park. A biologist wants to know if the mean number of parasites per butterfly is over 20. She will make her decision using a test with a level of significance of 0.10. The following informat

Hypothesis test interpretation.

An entrepreneur is considering the purchase of a coin-operated laundry. The present owner claims that over the past 5 years, the average daily revenue was $675 with a standard deviation of $75. A sample of 30 days reveals a daily average revenue of $625. If you were to test the null hypothesis that the daily average revenue w

Answers to Hypothesis Testing Questions in Excel

I am having trouble with some stats problems. Can you assist me? Thanks in advance The NPC, Inc. is a large mail order company that ships men's shirts all over the United States and Canada. They ship a large number of packages from their warehouse in Delta, Ohio. Their goal is to have 95 percent of the shipments delivered

Inferring about population Means

In random samples of 12 from each of two normal populations, we found the following statistics: Xbar1 = 74 S1= 18 Xbar2 = 71 S2 =16 a) Test with α= .05 to determine whether we can infer that the population means differ. b) Repeat part a increasing the standard deviations to S1= 210 and S2 =198. c) Describe what

data generated during pre/post treatment surveys

Inspection of student data generated during pre/post treatment surveys shows that among 10 subjects, 7 had higher scores after an experimental treatment, 2 had lower scores, and 1 score did not change. Using the traditional method of hypothesis testing, we need to determine if the experimental course has any effect. Use an alpha

Answering Hypothesis Testing Questions in Excel

A business student claims that on average an MBA student is required to prepare more than five cases per week. To examine the claim, a statistics professor asks a random sample of ten MBA students to report the number of cases they prepare weekly. The results are exhibited here. Can the professor conclude at the 5% significan

Hypothesis Testing on Men's Spending Habits

To see if young men ages 9 - 17 spend more or less than the average of $24.44 per shopping trip, the manager surveyed 33 young men and found the average amount spent was $22.67. The pop std us $3.70. At alpha 0.2, can it be concluded the average amount spent by the young men is not equal to $24.44 Perform appropriate hypoth

Differences Between Men and Women in Living Situations

A survey by the national institute of health asked a random sample of young adults (aged 19 to 25), "Where do you live now? That is, where do you stay most often?" We earlier compared the proportions of men and women who lived with their parents. Here now is the full two-way table (omitting a few who refused to answer and one w

Statistical Analysis on Dyes

The color of a fabric depends on the dye used and also how the dye is applied. This matters to clothing manufacturers, who want the color of the fabric to be just right. The study discussed in the previous exercise went on to dye fabric made of ramie with the same "procion blue" dye applied in two different ways. Here are the

Publishing Papers

Publishing scientific papers online is fast, and the papers can be long. Publishing in a paper journal means that the paper will live forever in libraries. The British Medical Journal combines the two: it prints short and readable versions, with longer versions available online. Is this OK with authors? The journal asked a r

Fatal Accidents Statistical Analysis

As part of a study on transportation safety, the U.S. Department of Transportation collected data on the number of fatal accidents per 1000 licenses and the percentage of licensed drivers under the age of 21 in a sample of 42 cities. Data collected over a one-year period follow. Please see the attached file for the table.

Hypothesis Testing

Assume that a hypothesis test of the given claim will be conducted. The college Dean of Admissions claims that the times students require to earn a bachelors degree have a mean less than five years. Which equality/inequality (e.g., =, =<, etc.) would use in the Null Hypothesis?

Hypothesis testing : Proportion

It has been reported that 80% of taxpayers who are audited by the IRS end up paying more money in taxes. Assume that the auditors are randomly assigned cases and that one of the ways the IRS oversees its auditors is to monitor the percentage of cases that result in the tax payer paying more in taxes. A sample of 400 cases handl

Statistical IQ Testing of Employees

Please explain the answers. Descriptions are in the file. 3. In order to test whether the mean IQ of employees in an organization is greater than 100, a sample of 35 employees is taken and the sample value of the computed test statistic, t_ = 3:5 The null and alternative hypotheses are: A) H0: X = 100; Ha: X 6= 100. B) H0:

Test Findings: sample of difference in wages based on gender

The wages data set has a sample size of 100 people that were surveyed. Our error margin was .05. For the 47 females surveyed the mean wage was $24,451 per year with a standard deviation of $12,455 per year. For the 53 males surveyed the mean wage was $36,492 per year with a standard deviation of $18,447 per year. Check the clai

Statistics - Hypothesis Testing Adjustment

Discuss the link between the estimate and the parameter in the context of an hypothesis test. Be sure to reference the appropriate steps of the five step process in your response, based on the steps below: Step 1: State null and alternate hypothesis. Step 2: Select a level of significance Step 3: Identify the test statisti