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# Hypothesis Testing

### Statistics - One-tailed or Two-tailed Test

1) How can you tell, from a verbal hypothesis statement, whether you are conducting a one-tailed or two-tailed test? 2) Suppose you were the manufacturer of a new and improved light bulb that you claim has an average service life more than twice the life of your nearest competitor's product. You want to test your product to b

### Non directional hypothesis - Get Super Slim X

Suppose the company that has produced "Get Slim X" now produces an even better diet pill. This new and improved version is called "Get Super Slim X." Health researchers say that the mean weight loss after taking this pill for six months should be 7 pounds. A random sample of 49 people, who want desperately to lose weight, tak

### Single Sample t-test - Five Step Hypothesis Testing - Given the Life expectancy data for the countries of the E.U., can we conclude that the mean Life Expectancy in the U.S. is greater than the mean Life expectancy in the E.U.? ...

Given the Life expectancy data for the countries of the E.U., can we conclude that the mean Life Expectancy in the U.S. is greater than the mean Life expectancy in the E.U.? Bring to mind a real-world situation or problem that could be addressed using a single-sample t test. For this situation or problem: Clearly identif

### Five Step Hypothesis Testing - Given the Life expectancy data for the countries of the E.U., can we conclude that the mean Life Expectancy in the U.S. is greater than the mean Life expectancy in the E.U.?

Given the Life expectancy data for the countries of the E.U., can we conclude that the mean Life Expectancy in the U.S. is greater than the mean Life expectancy in the E.U.? ? Bring to mind a real-world situation or problem that could be addressed using a single-sample t test. For this situation or problem: o Clearly ide

### Test of Independence - Electronic Orders by Industry

See the attached file. Businesses are increasingly placing orders online. The Performance Measurement Group collected data on the rates of correctly filled electronic orders by industry (Investor's Business Daily, May 8, 2000). Assume a sample of 700 electronic orders provided the following results. See attachment for table.

### Goodness of Fit Test - Percentage of Payment Methods

The American Bankers Association collects data on the use of credit cards, debit cards, personal checks, and cash when consumers pay for in-store purchases (The Wall Street Journal, December 16, 2003). In 1999, the following usages were reported. In Store Purchase Percentage Credit Card= 22% Debit Card=

### Candy Color Percentages for M&M

M&M/MARS, makers of M&M Chocolate Candies, conducted a national poll in which more than 10 million people indicated their preference for a new color. The tally of this poll resulted in the replacement of tan-colored M&Ms with a new blue color. IN the brochure "Colors," made available by M&M/MARS Consumer Affairs, the distribut

### Inferences about Two Population Variances on Earnings

The standard deviation in the 12-month earnings per share for 10 companies in the airline industry was 4.27 and the standard deviation in the 12-month earnings per share for 7 companies in the automotive industry was 2.27 (Business Week, August 14, 2000). Conduct a test for the equal variances at a=.05. What is your conclusion

### Inferences about Two Population Variances

Media Matrix and Jupiter Communications gathered data on the time adults and the time teens spend online during a month (USA Today, September 14, 2000). The study concluded that on average, adults spend more time online than teens. Assume that a follow-up study sampled 26 adults and 30 teens. The standard deviations of the time

### Hypothesis Testing Grocery Bills in Different Towns

A study is performed in a large southern town to determine whether the average weekly grocery bill per four person family in the town is significantly different from the national average. A random sample of the weekly grocery bills of four person families in this town is given in the attached file. a. Assume that the national

### A sample of n=9 scores is obtained from a normal population distribution with o-=12.

A sample of n=9 scores is obtained from a normal population distribution with o-=12. The sample mean is M=60. a- with a two-tailed test and o=.05,use the sample data to test the hypothesis that the population mean is u=65. b- with a two-tailed test and o=.05, use the ample data to test the hypothesis that the population me

### Important information about Introduction to Hypothesis Testing

The value of the z-score that is obtained for a hypothesis test is influenced by several factors. Some factors influence the size of the numerator of the z -score and other factors influence the size of the standard error in the denominator. For each of the following, indicate whether the factor influences the numerator or denom

### Statistics - Hypothesis Testing for IQ Scores

Numerous studies have shown that IQ scores have been increasing, generation by generation, for years (Flynn, 1984, 1999). The increase is called the Flynn Effect, and the data indicate that the increase appears to be about 7 points per decade. To demonstrate this phenomenon, a researcher obtains an IQ test that was written in

### An automotive part must be machined to close tolerances to be acceptable to customers. ...

An automotive part must be machined to close tolerances to be acceptable to customers. Production specifications call for a maximum variance in the lengths of the parts of .0004. Suppose the sample variance for 3 parts turns out to be S2 = .0005. Use a=.05 to test whether the population variance specification is being violate

### Hypothesis Testing: Jail Time of Convicted Embezzlers

A law student, who want to check a professor's claim that convicted embezzlers spend on average 12.3 months in jail, takes a random sample of 36 such cases from court files. Using his results, namely, a mean of 10.8 months and a standard deviation of 3.9 months, test the hypothesis u=12.3 versus the alternative hypothesis u≠12

### Hypothesis Testing

A study of 20 families in a certain large city showed that the average income was \$33,210 in 2000 with a standard deviation of \$1800. Test the hypothesis that the true average income in this city was actually \$31,000 against the hypothesis that it was more. Use a level of significance of 5% (hint: This is a one-sided test).

### Hypothesis Testing - NASDAQ Annual Rates of Return

The following data on annual rates of return were collected from five stocks listed on the New York Stock Exchange ("the big board") and five stocks listed on NASDAQ. At the .10 significance level, can we conclude that the annual rates of return are higher on the big board? NYSE.......Nasdaq 17.16.........15.80 17.08.......

### Hypothesis Testing

Fry Brothers Heating and Air Conditioning, Inc. employs Larry Clark and George Murnen to make service calls to repair furnaces and air conditioning units in homes. Tom Fry, the owner, would like to know whether there is a difference in the mean number of service calls they make per day. A random sample of 40 days last year showe

### Test a Hypothesis Mean Speed

Officials want to test whether drivers are obeying the posted speed limit of 65 mph. Sample: 55 vehicles. Average speed of sample: 69 miles Standard deviation: 7 miles 95% confidence level desired. Test the hypothesis that mean speed is less than or equal to 65 mph against its one-sided alternative. Please see the attac

### Statistics in business - 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. ...

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

### P-value

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

### A Discussion On Right-Tail P-Values

Faced with rising fax costs, a firm issued a guideline that stated that those 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 wi

### Hypothesis Testing - Fry Brothers Heating and Air Conditioning, Inc. employs Larry Clark and George Murnen to make service calls to repair furnaces and air conditioning units in homes. ...

List the data elements you are provided or can calculate. How do you use these data elements to determine how to solve the problem? Fry Brothers Heating and Air Conditioning, Inc. employs Larry Clark and George Murnen to make service calls to repair furnaces and air conditioning units in homes. Tom Fry, the owner, would like

### Hypothesis Testing

A food processor is concerned that the 16 ounce can of sliced pineapple is being overfilled. The quality control department took a random sample of 50 cans and found that the arithmetic mean weight was 16.05 ounces, with a sample standard deviation of .03 ounce. At the 5% significance, can the hypothesis that the mean weight i

### Hypothesis Testing - Research Question - Clearly identify the independent and dependent variables you would study. Determine whether a one-tail or two-tail test is most appropriate and explain why. ...

For this research question: Clearly identify the independent and dependent variables you would study. Determine whether a one-tail or two-tail test is most appropriate and explain why. Generate a testable null statistical hypothesis and an alternative statistical hypothesis. Select an alpha level of .05, .01, or .001 and

### Testing of Hypothesis-Natur of Z statistic

1. The value of the z-score that is obtained for a hypothesis test is influence by several factors. Some factors influence the size of the numerator of the z-score and the factors influence of the standard error in the denominator. For the following, indicate whether the factor influences the numerator or denominator of the z-

### Hypothesis Testing - Gender and Blood Pressure

Are females more likely to develop high blood pressure than males? For this research question: Clearly identify the independent and dependent variables you would study. Determine whether a one-tail or two-tail test is most appropriate and explain why. Generate a testable null statistical hypothesis and an alternative

### Hypothesis Testing - Shopping Time for Women with Children

The mean shopping time for women with kids is 7.3 minutes. A random sample of women with children in a shopping store gave the following shopping times in minutes: 7.7 8.1 8.2 9.0 5.8 9.3 8.4 6.9 12.1 9.4 8.1 6.2 7.3 7.9 8.2 8.5 7.2 6.3 9.1 8.8 a) Verify that mean=8.1 minutes and s=1.4

### Glucose Levels Hypothesis Testing

Over the past 8 weeks the horse readings (in mg/100 ml)were 93, 88, 82, 105, 99, 110, 84, and 89. If the sample mean is 93.8, letting x be the random variable, we assume that x has a normal distribution and we know that the population standard deviation is 12.5. The mean glucose level for the horse should be u(population mean)=8

### Fry Brothers Heating and Air Conditioning P-value Calculation

Fry Brothers Heating and Air Conditioning, Inc. employs Larry Clark and George Murnen to make service calls to repair furnaces and air conditioning units in homes. Tom Fry, the owner, would like to know whether there is a difference in the mean number of service calls they make per day. A random sample of 40 days last year showe