a) What is the difference between a normal distribution and a standard normal distribution? b) What is the purpose of using a standard normal distribution instead of the normal distribution? c) Please cite one example of how the standard normal distribution is used, including the Z-values for your example. d) If you
Tourism is one consideration for CoffeeTime's future, A survey of 1,233 visitors to mumbai last year revealed that 110 visited a small cafe during their visit. Laura claims that 10% of tourists will include a visit to a cafe.
1. A financial analyst wants to compare the turnover rates, in percent, for shares of oil-related stocks versus other stocks, such as GE and IBM. She selected 32 oil-related stocks and 49 other stocks. The mean turnover rate of oil-related stocks is 31.4 percent and the standard deviation 5.1 percent. For the other stocks, the m
1. The following is a hypothetical set of anxiety scale scores from a population of students being seen at a college counseling center: 5 16 47 6 18 50 9 25 50 10 46 50 12 47 78 What are the Z and the T scores of the person who scored 6? 18? Of the two people who scored 47? Of the person who scored 78? Why is it not a
Clark Heter is an industrial engineer at Lyons Products. He would like to determine whether there are more units produced on the afternoon shift than on the day shift. A sample of 54 day-shift workers showed that the mean number of units produced was 345, with a standard deviation of 21. A sample of 60 afternoon-shift workers sh
2) In 1999 the Center of Disease Control estimated that about 34.8% of high-school students smoked cigarettes. They established a national health goal of reducing that figure to 16% by the year 2010. To that end, they hoped to achieve a reduction to 30% by the end of 2001. Early in 2002 they released a research study in which on
I am doing a project where I am comparing the accuracy and reproducibility of 3 different force gauges with varied angles and applied pressures. All of the gauges have a 50 lb. capacity. They will all be tested with 0-30 lbs in 5 lb increments of applied load/pressure. They will also be tested at 0 degrees (true perpendicular)
Let X... We observe X=9 out of n=15. Is the battery more likely to last more than 5 years? Please see the attached file for the fully formatted problems.
For a number of years... In the first year after the change, there were 56- survivors in a class of 800. Is this increase explainable as simply sampling variability? Test at a=0.01. Please see attached.
Seven skulls... Use these statistics in a test of the hypothesis that these skulls belong to a race previously found nearby in which the average width if known to be 146mm. Assume a nearly normal population. Perform the test a=0.1. Please see attached.
Perform each of the steps below using Excel. Use the collected data from the chart (MLB Statistics) as a sample of the population (Any one statistic you choose). Describe the population that the data represents. Interpret each of your results with a conclusion and decision. Use any statistic on the MLB chart to answer the questi
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
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:
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
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
State the hypothesis, set the criterion for rejecting the Ho, compute the test stat, construct the CI, and interpret the results.
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
Do these data present evidence that one form of travel guide is better than the other? Test for a reduction in cost from 1990 to 1995. Using these data, do you believe that customer satisfaction is increased, on the average, after the new management decision and the resulting new company policy? Construct a 95% confidence interval for the regression coefficient. Is there statistical evidence (at 0.05 level of significance) of a linear correlation between the two variables? Based on these results, should the manager shift the proportions of the fund invested in the three countries? How confident are you of your answer? Construct a complete ANOVA table for this problem.
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
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
Given a random sample of data and a hypothesis, how do I set up the problem to perform tests at specific significance levels?
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
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?