26. To obtain information on the corrosion-resistance properties of a certain type of steel conduit, 45 specimens are buried in soil for a 2-year period. The maximum penetration (in mils) for each specimen is then measured, yielding a sample average penetration of x-bar= 52.7 and a sample standard deviation of s = 4.8. The condu
Does correlation equal causation? Why or why not? What is the relationship between correlation and association? What is association? When would you use regression correlation at your place of employment, in your education, or in politics? How do you identify outliers in your data? What are the differences between
3-8. For each of the following, (a) indicate what two populations are being compared, (b) state the research hypothesis, (c) state the null hypothesis, and (d) say whether you should use a one-tailed or two-tailed test and why. (i) Do Canadian children whose parents are librarians do better than Canadian children in general
Are there other methods besides ANOVA that can be used to evaluate whether the difference in means between TWO OR MORE samples is significant? For what types of distributions? I am looking for clarity in addition to what can be done for a normal distribution.
Using AIU's large data base of survey responses from unit 2 Individual project (keep in mind this data base is your sample), you will begin testing hypothesis. Complete all of the following: 1. Test a hypothesis to see whether the average overall job satisfaction (in the population of all workers in the USA) is equal to 4.5=.
Ms Lisa is the budget director for the New Process Company. She would like to compare the daily travel expenses for the sales staff and the audit staff. She collected the following sample info: Sales ($) 131 135 146 165 136 142 Audit ($) 130 102 129 143 149 120 139 At the .10 confidence level, canshe conclude that the mea
Use the 5 step hypotheis testing procedure to solve The Gibbs baby food company wishes to compare the weight gain of infants using their brand versus their competitor's. A sample of 40 babies using the Gibbs products revealed a mean weight gain fo 7.6 pounds in the 1st 3 months after birth. The standard deviation of the sampl
Scenario: Your company must make a decision about a very large investment. An internal study shows that if demand for your product increases substantially from the current levels, new production lines must be set up to meet the demand at a reasonable cost and an acceptable quality level. Trying to meet the demand with current fa
A prof. can't decide how to vote on a tuition increase for the students at her univ. The incrase is supposed to pay for new student parking and there appears to be mixed feelings. The prof. decides to do her own survey. If the proportion fo her students supporting the tuition increase exceeds .70, she will vote to support an inc
1. The recent boom in sales of travel books has led to the marketing of other travel related guides, such as video travel guides and audio walking tour tapes. Barnes and noble has been studying the market for these travel guides. In one market test, a random sample of 25 potential travelers was asked to rate audiotapes of a cert
Please see attached file. Please show all work. ... is there sufficient evidence to support her claim at a α = 0.05 significance level? (see attachment for complete question)
Using a hypothesis test with a well known 4 step procedure, state your conclusion for the 0.05 significance level: A. Based on responses from 1,015 randomly selected teens, which concluded that 44% of teens say grades are the greatest source of pressure, test the claim that fewer than half of all teens in the population feel
1) Without computing a P-value, determine whether the alternative hypothesis is supported. The alternative hypothesis, a sample mean, a sample standard deviation, a claimed population mean and a sample size are given. Explain by making a "sketch" of the distribution of sample means and showing location of the sample mean. Ha
Alcohol appears to be involved in a variety of birth defects, including low birth weight and retarded growth. A researcher would like to investigate the effect of prenatal alcohol on birth weight. A random sample of n=16 pregnancy rates is obtained. The mother rats are given daily doses of alcohol. The average weight for the sam
Question: A researcher is using a sample for n=16 lab rats to examine the effect of a new diet drug. It's known that under regular circumstances these rats eat an average of 10 grams of food each day. The distribution of food consumption is normal with a standard deviation=4. The expected effect for the drug is to reduce food co
Test a hypothesis to see whether the average overall job satisfaction (in the population of all workers in the USA) is equal to 4.5 with a = .05. *Please see attachment for data. Thanks.
Your car gets 29 miles per gallon, one day you see your mileage average is 28 miles per gallon. Is this change statistically significantly and would you look for a reason or is it more of a variation attributed to chance? Another day you see your mileage is 22 miles per gallon - Is this change statistically significantly and
How do you determine if a process is in or out of control and what is the significance of having appropriate significance levels (0.05, 0.01, 0.1, etc.)?
Given a random sample of data and a hypothesis, how do I set up the problem to perform tests at specific significance levels?
42. Refer to the Baseball 2000 data in Appendix D, which reports information on the 30 Major League Baseball teams for the 2000 season. a. At the .10 significance level, is there a difference in the variation of the number of stolen bases among the teams that play their home games on natural grass versus on artificial turf?
10. The manager of a computer software company wishes to study the number of hours top executives spend at their computer terminals by type of industry. The manager selected a sample of five executives from each of three industries. At the .05 significance level, can she conclude there is a difference in the mean number of hours
The production manager at Bellevue Steel, a manufacturer of wheelchairs, wants to perform a second analysis of the number of defective wheelchairs produced on the day shift and afternoon shift. A sample of the production from 6 day shifts and 8 afternoon shifts revealed the following number of defects. At the 0.05 significanc
Hypothesis Testing for Proportions.
1. If I have a degree of freedom equal to 4 with a significance level of .01. Would there be enough evidence to support a claim with a test statistic equal to 13.5? Would this support or reject the null hypothesis if the null hypothesis supports the claim?
The critical region or rejection region is the set of all values of the test statistic that causes what to the null hypothesis?
Please help answer the following questions involving statistics. 1. Why do we use hypothesis testing? 2. What is a test statistic and how is it related to a critical value in hypothesis testing? 3. What is the critical region in hypothesis testing and why is it important?
1) The nationwide mean price for a 3-year old Honda civic is $8,500 with a known standard deviation of $600. You check the newspaper and find nine 3-year old Civics in San Francisco selling for an average price of $9,000. You wonder whether the cost of Civics in San Francisco is higher than the rest of the nation. a) State yo
1. To compare the current attitudes toward prayer in the schools, a survey was conducted in four southern California counties {see attached for results}. State your hypotheses and conduct a test for homogeneity of attitudes among the four counties concerning prayer in the schools. Use a P-value in your conclusion. It would N
A taxi company manager is trying to decide if the use of radial tires instead of regular belted tires improves fuel economy. As a test, twelve cars are equipped with belted tires and the cars are driven over a prescribed test course. Without changing drivers the same cars were then equipped with the radial tires and driven once
A survey was completed to estimate the proportion of residents in support of constructing a new football stadium, at tax payer expense, to accommodate an NFL team in the LA area. It was found that 71 of 100 LA city residents favored the construction while 78 of 135 residents in the rest of the county were in support. Determine i