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Hypothesis Testing

Significance of the Difference Between Two Sample Means

I need help with this problem. I already know the answer. I am confused between the lectures, textbook, and work text. Can you show me, the old fashioned way (not Excel, SPSS or any other software to generate the answer), I need the formulas to show how to come up with the correct answer? Here is the problem: An experim

Scatter plot, correlation coefficient, and a hypothesis test

(a) Make a scatter plot of the data. What does it suggest about the correlation between X and Y? (b) Use Megastat or Excel to calculate the correlation coefficient. (c) Use Excel to find t.05 for a two-tailed test. (d) Calculate the t test statistic (e) Calculate critical value of ra. (f) Can you reject p=0? Orders(X)

Relationship between levels of significance and rejecting the null

1-The lower the level of significance, the harder it is to reject the null. In sum, you want to be REALLY sure that your alternative hypothesis is correct, so if you use a low significance level (say, .01), then you would only reject the null if you're REALLY sure about the outcome. Most use a .05 level of significance, which

Hypothesis Testing for prospective cohort study

A recent prospective cohort study analyzed the effect of calcium plus vitamin D supplement use on the development of osteoporosis (weak and brittle bones). QUESTION 11 What are the null and alternative hypotheses being investigated in this study? (Be sure to specify the exposure-outcome association under study along with t

Hypothesis test: population proportion

CherryBerry Soda, Inc. claims that 15 percent of the population can identify its products. In efforts to boost their identity, CherryBerry employs a famous spokesperson to advertise. A survey is then taken to assess the results of the ad campaign. The results show that 17 percent of the 1000 respondents can identify CherryBerry

Hypothesis Testing: Mean Time to Learn a New Software Program

A recent article in a computer magazine suggested that the mean time to fully learn a new software program is 40 hours. A sample of 100 first-time users of a new statistics program revealed the mean time to learn it was 39 hours with the standard deviation of 8 hours. At the 0.05 significance level, can we conclude that users le

Hypothesis Test for Houses with Pools in Southern California

For several decades, it was a common practice in Southern California for houses to be built with pools in the backyard (as any airplane flight which ends at a Southern California airport will reveal). Now, however, that practice may be changing, possibly because of the recent demand for landscaped homes, which experts believe he

Using a hypothesis test to determine if unsafe Radon levels vary by region.

Radon is a gas produced when radium decays, and it can enter homes where it can become a health threat. Among 186 homes in Hyde Park, New York (home of Franklin D. Roosevelt), 16% were found to have unsafe radon levels (above 4 picocurries per liter). Among 237 homes in LaGrange, New York (home of the author), 19% were fou

Hypothesis Test: Difference of Proportions

The general social survey is an annual survey given to about 1,500 U.S. adults selected at random. Each year, the survey contains several questions meant to probe the respondents' views of employment. A recent survey contained the question "How important to your life is having a fulfilling job?" Of the 264 college graduates su

Hypothesis test for difference in means across populations

A sample of 40 investment customers serviced by an account manger are found to have had an average of $23,000 in transactions during the past year, with a standard deviation of $8500. A sample of 30 customers serviced by another account manager averaged $28,000 in transactions, with a standard deviation of $11,000. Assuming th

For each of the following pair of null and alternative hypotheses, determine whether the pair would be appropriate for a hypothesis test. If a pair is deemed inappropriate, explain why.

For each of the following pair of null and alternative hypotheses, determine whether the pair would be appropriate for a hypothesis test. If a pair is deemed inappropriate, explain why. a. Ho: mu/10, H1: mu < 10 b. Ho: mu = 30, H1: mu &#8800; 30 c. Ho: mu > 90, H1: mu <= 90 d. Ho: mu <= 75, H1:mu <= 85 e. Ho: x-bar =

1) Using the confidence interval when conducting a two-tail test for the population mean we do not reject the null hypothesis if the hypothesized value for 2) Does this sample indicate a smaller average?

1) Using the confidence interval when conducting a two-tail test for the population mean we do not reject the null hypothesis if the hypothesized value for a. is to the left of the lower confidence limit b. is to the right of the upper confidence limit c. falls between the lower and upper confidence limits d. falls in th

One-Tailed and Two-Tail Hypothesis Tests

1) For a simple random sample , n= 700 and p= 0.63. At the 0.025 level, test H0: &#960; &#8804; 0.60 versus H1: &#960; 0.60 (&#960; this symbol represents Pi) 2) The director of admissions at a large university says that 15% of high school juniors to whom she sends university literature eventually apply for admission. IN a

During 2002, college work - study students earned a mean of $1252. Assume that a sample consisting of 45 of the work-study students at a large university was found to have earned a mean of $1277 durin

During 2002, college work - study students earned a mean of $1252. Assume that a sample consisting of 45 of the work-study students at a large university was found to have earned a mean of $1277 during the year, with a standard deviation of $210. Would a one-tail test at the 0.05 level suggest the average earnings of this univer

Hypothesis test: variance

Use a 0.05 significance level to test the claim that the heights of female supermodels vary less than the heights of women in general. The standard deviation of heights of the population of women is 2.5 in. Listed below are the heights (in inches) of randomly selected supermodels (Taylor, Harlow, Mulder, Goff, Evangelista, Aue

Hypothesis Test for Manufacturing Aircraft Altimeters

The Stewart Aviation Products Company uses a new production method to manufacture aircraft altimeters. A simple random sample of 81 altimeters is tested in a pressure chamber, and the errors in altitude are recorded as positive values (for readings that are too high) or negative values (for readings that are too low). The samp

Hypothesis Testing of Diastolic Blood Pressure

A local newspaper alleges that workers at my brother's café have an extremely stressful job. Stresses come from a combination of physical and social sources such as incessant time pressure, unruly customers like Indiana Jones, and bad salads. It gets so bad that Médecins Sans Frontières decides to step in and invest

Testing Hypothesis To Identify Test Statistic, P-Value & Critical Value

In these two exercises, test the given claim. Identify the null hypothesis, alternative hypothesis, test statistic, P-value or critical value(s), conclusion about the null hypothesis, and final conclusion that addresses the Original claim. Use the P-value method unless your instructor specifies otherwise. Analysis of Last

Testing Claims About Proportions ...

Test the given claim. Identify the hypothesis, alternative hypothesis, test statistic, P-value or critical value(s), conclusion about the null hypothesis, and final conclusion that addresses the original claim. Use the P-value method unless your instructor specifies otherwise. Drug Testing of Job Applicants In 1990, 5.8% o

Hypothesis Testing for Survey Workers

Survey of Workers In a survey of 703 randomly selected workers, 15.93% got their jobs through newspaper ads (based on data from Taylor Nelson Sofres Intereach). Consider a hypothesis test that uses a 0.05 significance level to test the claim that less than 20% of the workers get their jobs through newspaper ads. a. What is t

Hypothesis Testing ...

An auditor received 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

Statistics - Right Tail P-value

I am having major problems identifying formulas, assigning values, & recognizing symbols. This is because I had the 1st class in 2006, and this 2nd class should have followed immediately, but the academic counselors chose to assign other classes first. Now, I remember very little, & the instructor advises that I need to be ref

Hypothesis Testing explained in this solution

9.54 Faced with rising fax costs, a firm issued a guideline that transmissions of 10 pages or more should be sent by 2-day mail instead. Exceptions are allowed, but they want the average to be 10 or below. The firm examined 35 randomly chosen fax transmissions during the next year, yielding a sample mean of 14.44 with a standard