Stress levels of three different classes of physics students were measured on a scale of 1 to 20, with 20 being the greatest level of stress. At a 0.05 significance level, are the stress levels equal among all remaining students at the end of week 5 in all three classes? Class #1 Class #2 Class #3 9 13 10 7 20
A sample of 120 observations revealed that p = .30. At the 0.05 significance level, can the null hypothesis be rejected? a) state the decision rule b)compute the value of the test statistic c)what is your decision regarding the null hypothesis?
A random sample of 15 observations provided x-bar = 182 and s = 12. (a) Test H0: μ = 190 versus H1: μ < 190 at α = .05. State your assumption about the population distribution. (b) What can you say about the P-value of the test statistic calculated in part (a)? A weight loss program advertises "LOSE 40 P
Need help setting up, understanding and solving this problem: At Western University the historical mean of scholarship examination scores for freshman applications is 900. A historical population standard deviation σ = 180 is assumed known. Each year, the assistant dean uses a sample of applications to determine whether
A sample of 500 respondents was selected in a large metropolitan area in order to determine information concerning consumer behavior. Among the questions asked was "Do you enjoy shopping for clothing?" Of the 240 males, 136 answered "Yes". Of the 260 females, 224 answered "Yes". 5.1 Is there evidence of a difference in th
1. Does using statistics as the sole basis for making a decision eliminate the need for ethical considerations? Why or why not? What role do ethics play when performing statistical testing?
Need help setting up, solving and understanding this problem: During the 2004 election year, new polling results were reported daily. In an IBD/TIPP poll of 910 adults, 503 respondents reported that they were optimistic about the national outlook, and The President's leadership index jumped 4.7 points to 55.3. a. What is
The cost of a one-carat VS2 clarity, H color diamond from Diamond Source USA is $5600. A Midwestern jeweler makes calls to contacts in the diamond district of New York City to see whether the mean price of diamonds there differs from $5600. a. Formulate hypotheses that can be used to determine whether the mean price in New Yo
Problem #1 Independent random samples of 36 and 50 observations are drawn from two quantitative populations, 1 and 2, respectively. The sample data summary is shown here: Sample 1 Sample 2 Sample Size 36 50 Sample Mean 1.28 1.35 Sample Variance 0.058 0.056 Do the data prese
Problem #1 A total of 200 people in each of three grocery stores were asked if they favored, opposed, or were indifferent to the sale of lottery tickets in grocery stores. The results of the survey are summarized below. Test the hypothesis at α= 0.05. Opinion Store A Store B Store C Favor 21 78 94 Oppose 101 63
The historical reports from two major networks showed that the mean number of commercials aired during prime time was equal for both networks last year. In order to find out whether they still air the same number of commercials on average or not, random and independent samples of 85 recent prime time airings from both networks
An automobile assembly line operation has a scheduled mean completion time, mean, of 14.7 minutes. The standard deviation of completion times is 1.2 minutes. It is claimed that, under new management, the mean completion time has decreased. To test this claim, a random sample of 60 completion times under new management was taken.
Factories are being compared to see if there is a difference in the average defect rates of the chips they produce. In the first factory 250 chips are sampled, In the 2nd factory 350 chips are sampled. Proportions of defective chips are 4.0% and 6.0% respectively. Using a confidence level of 95%. Which statement is supported by
The mall has two stores, one located on Street 1 and other on Street 2. Tow stores are laid out differently but both store managers claim their layout maximizes the amounts customers will purchase on impulse. A sample of 10 customers at Street 1 store revealed they spent the following amounts more than planned: 17.5, 19.73, 12.6
A counseling psychologist is interested in determining whether the perception of a counselor's expertise is affected by the approach the counselor utilizes. In particular, the counseling psychologist is interested in contrasting a rational-emotive approach with a client-centered approach using an instrument that rates perceptio
(1) null vs. alternative hypotheses? (2) real-world example of a single-sample t test. (3) what is effect size?
I am having some difficulties with understanding exactly what I need to do. I know how to obtain my independent and dependent variable, however, I am having trouble bringing together being able to generate the statistical null and alternative hypotheses. Using one of the following: Ho: mu = (hypothesized value) vs.
The Federal Government recently granted funds for a special program designed to reduce crime in high-crime areas. A study of the results of the program in eight high-crime areas of Miami, Florida, yielded the following results. Number of Crimes by Area A B C D E F G H Before 14 7 4 5 17 12
The cost of an e-commerce website can vary a great deal. A market research team hypothesized that the cost of an average website is $3500. Ho mean = $3,500 H1 mean ? $3,500 The sample data obtained showed the following costs: 2000, 3000, 3500, 3900, 6000, 7000, 10000, 12000, 14900, 19900, 6990, 9990, 2400 I n
A sociologist wanted to determine which academic subject high school students preferred. The hypotheses she wishes to test are: Ho: The percentage of female high school students who prefer mathematics is equal to the percentage of male students who prefer mathematics. H1: The percentage of female high school students who p
A supermarket advertises that the waiting time spend by customers waiting in line at the cash register is uniform between 0 and 6 minutes. A number of customers complain that they wait in line too long for this to be true. Joel, the manager, decides to test whether the complains are justified by testing the hypotheses: Ho: µ
There are two boxes, Box A and Box B. Box A has 40 tags with the number 1, 50 tags with the number 10, and 10 tags with the number 100. Box B has 40 tags with the number 100, 50 tags with the number 10, and 10 tags with the number 1. A box is picked at random and exactly one tag is drawn at random from that box. You do not know
At the time she was hired as a server at the restaurant, Beth was told, "You can average more than $20 a day in tips." Over the first 31 days she was employed, the mean daily amount of her tips was $21.76, with a standard deviation of $2.35. At the 0.01 significance level, can Beth conclude she is earning more than $20 in ti
Calculate and interpret the appropriate statistical test to determine the relationship between the following two variables. Use the five-step model of hypothesis testing to draw conclusions at the .05 level of significance Class Frequency of Drug Use Freshman Sophomore Junior Senior Never 16 8 30 28 1 or 2 20 25 22 1
Calculate and interpret the appropriate statistical test to determine the relationship between the following two variables. Use the five-step model of hypothesis testing to draw conclusions at the .05 level of significance Gender College Major Male Female Psychology 11 9 Educatio
A recent national survey found that high school students watched an average (mean) of 6.8 videos per month. A random sample of 36 college students revealed that the mean number of videos watched last month was 6.2, with a standard deviation of 0.5. At the .05 significance level, can we conclude that college students watch fewer
When would you use a one-tailed rather than a two-tailed t-test when checking significance levels?
H0 = H1 =  (Uppercase Sigma) =  (Mu) =  (Lowercase Sigma) = s = s2 = X bar (x-bar) = ρi (rho sub i) = πi (pi sub i) = d.f. = α (alpha) = p-value +
Am having difficulty plugging in the correct values into the formulas to be sued. If you can please provide step by step work out of the following problems. Begin with formula to be used and then work out so i can see where values go I would appreciate it. 2) A biologist suspected that in the 20-24 age group, males have a hi
1) What is more important for the researcher to be concerned about in a study, Type I or Type II errors? Why? How does the type of data collected and the way in which the data is collected affect the possibility of Type I or Type II error? 2) Give two examples when practical significance would outweigh statistical signific
1. In research, one often hopes to be able to state results using a confidence level that the results are valid of 90% or more. To test results to determine the confidence level, what is the significance of locating the test statistic in the tail that has a probability less than ά, which implies a confidence level of 1-(alp