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 s1 and s2 be used in place of the population standard deviations σ1 and σ2 ?
Please see the attached file for the fully formatted problems. 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 t
1. Explain the difference between a left-tailed, two-tailed, and right-tailed test. When would we choose a two-tailed test? How can we tell the direction of the test by looking at a pair of hypothesis? How can we tell which direction (or no direction) to make the hypothesis by looking at the problem statement (research questio
The hypothesis should be developed to include an assessment of women with similar education and work experiences earn less money than men with similar qualifications. The data set and legend are included as an attachment. Please provide a five-step hypothesis test with the data relevant to the selection (data set and legend
"A recent article in The Wall Street Journal reported that the 30-year mortgage rate is now less than 6 percent. A sample of eight small banks in the Midwest revealed the following 30-year rates (in percent): " 4.8 5.3 6.5 4.8 6.1 5.8 6.2 5.6 At the .01 significance level, can we concl
In testing the equality of the two means below, what is the test statistic? (Use the equal variances formula). Sample 1 Sample 2 Sample size 12 8 Sample mean 115 80 Sample variance 700 450 A) 0.28 B) 3.27 C) 2.37 D) 0.1
A pharmaceutical company is testing the effectiveness of a new drug for lowering cholesterol. As part of this trial, they wish to determine whether there is a difference between the effectiveness for women and for men. At = .05, what is the test value? Women Men Sample size 40 70 Mean effect 7 6.75 Sample varianc
Explain the difference, if any, between a 1-tailed test and a 2-tailed test.
Problem 1 Consider the Mission Valley Power Company (MVP), which has over 6000 customers. In response to a request from the Michigan Public Utilities Commission, MVP needs to estimate the average kilowatts of electricity used by customers on April 1. The only way to get this number is to select a random sample of customers and
Comparing ages of a Marathon Runners: Use a 0.05 significance level to test the claim that for the runners in the New York City marathon, men and women have ages with different amounts of variation.
Tobacco and Alcohol Use in Animated Children's Movies: Lists times (in seconds) that animated children's movies show tobacco use and alcohol use. The 50 times of tobacco use have a mean of 57.4 sec and a standard deviation of 104.0 sec. the 50 times of alcohol use have a mean of 32.46 sec and a standard deviation of 66.3 sec.
PROBLEM SET II ALTERNATE 1 9-11. The owner of Britten's Egg Farm wants to estimate the mean number of eggs laid per chicken. A sample of 20 chickens shows they laid an average of 20 eggs per month with a standard deviation of 2 eggs per month. a. What is the value of the population mean? What is the best estimate of this v
A recent survey indicated that the average amount spent for breakfast by business managers was $7.58 with a standard deviation of $0.42. It was felt that breakfasts on the West Coast were higher than $7.58. A sample of 81 business managers on the West Coast had an average breakfast cost of $7.65. At a= 0.05, what is the t
Using the z table in Table E of Appendix C, what are the critical values for a two-tailed test when a=0.03. A) ± 2.17 B) ± 2.05 C) ± 2.33 D) ± 1.88
To encourage telephone efficiency, a catalog call center issues a guideline that at least half of all telephone orders should be completed within 2 minutes. Subsequently, a random sample of 64 telephone calls showed that 40 calls lasted over 2 minutes. (a) At α = .05 is this a significant departure from the guideline in
A study by the Investment Company Institution (ICI) in 2004, which randomly surveyed 3,500 households and drew upon information from the IRS. If found that 72% of households have conducted at least one IRA rollover from a an employer sponsored retirement plan. Suppose a recent random sample of 90 households in the greater Detr
Design (but not do) a test to see if genetically modified foods are different from non-genetically modified (NGM) foods. Assume you are designing a study that will analyze GM and NGM foods, and answer the following questions. 1. What will your null and alternative hypotheses be? (Hint: Ensure your null and alternative hypo
15.18 Sixty-four students in an introductory college economics class were asked how many credits they had earned in college, and how certain they were about their choice of major. Research question: At α = .01, is the degree of certainty independent of credits earned? Certainty Credits Earned Very Uncertain Somewhat Certai
Using the research question and data below conduct a equivalent nonparametric test of hypothesis below. The hypothesis for the ANOVA test is: H0: μ1=μ2=μ3=μ4=μ5=μ6=μ7=μ8=μ9 (all means are equal) H1: Not all means are equal (at least one is different) Telecommunication Servi
In Utica, Michigan, 205 of 226 school buses passed the annual safety inspection. In Detroit, Michigan, only 151 of 296 buses passed the inspection. (a) State the hypotheses for a right-tailed test. (b) Obtain a test statistic and p-value. (c) Is normality assured? (d) If significant, is the difference also large enough to be
You are interested in ratings of cell phone service by 5 different carriers. 10 people rate each of the five carriers. The data that you collect is the number of people who rated each of the services favorably and the number of people that rated each of these services unfavorably. Which test would be appropriate to use in thi
When/how would you use hypothesis testing at your place of employment/your education/or in politics?
The wall street journal reported 28% of people who bank online have cut back on their internet use. A credit union's manager is certain that while internet use may be down, it is much less than 28% of its customers. They are convinced that at most 10% of their customers have reduced their internet banking transactions. the cr
Please help with the following problem. A major issue facing many states is whether to legalize casino gambling. Suppose the govenor of one state believes that more than 55% of the state's registered voters would favor some form of legal casino gambling. However before backing a proposal to allow such gambling, the govenor
A major issue facing many states is whether to legalize casino gambling. Suppose the Governor of one state believes that more than 55% of the state's registered voters would favor some form of legal casino gambling. However, before backing a proposal to allow such a gambling, the Governor has instructed his aides to conduct a
The director of a state agency believes that the average starting salary for clerical employees in the state is less than $30,000 per year. To test her hypothesis, she collected a simple random sample of 100 starting clerical salaries from across the state and found that the sample mean is $29,750. 1: State the appropriate n
Provide the relevant critical value for each of the following circumstances: 1: HA: μ > 13, n = 15, σ = 10.3, Level of Significance = 0.05 2: HA: μ =/ 21, n = 23, s = 35.40, Level of Significance = 0.02
Refer to the Baseball data set posted which reports information on the 30 Major League Baseball teams for the 2002 season. a. At the .05 significance level, can we conclude that there is a difference in the mean salary of teams in the American League versus teams in the National League? Explain b. At the .05 signi
The Human Resources Director for a large company is studying absenteeism among hourly workers. A sample of 120 day shift employees showed 15 were absent more than five days last year. A sample of 80 afternoon employees showed 18 to be absent five or more times. At the 0.01 significance level can we conclude that there is a highe
Is the mean salary of accountants who have reached partnership status higher than that for accountants who are not partners? A sample of 15 accountants who have the partnership status showed a mean salary of $82,000 with a standard deviation of $5,500. A sample of 12 accountants who were not partners showed a mean of $78,000 wi