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    Stratified Random Sampling

    Jane chooses every 20th person in the campus phone book to call for her interview study. Justin identifies important subgroups in the campus population, then selects participants so that his sample had the same proportions of each important group, as the population does. What type of sampling occurs?

    Sample Assumption

    Runout obtained for 38 gears laid and 39 gears hung after heat treating. Mean laid runout=12.6, Mean hung runout=17.9 Gears laid- 5,8,8,9,9,9,9,10,10,10,11,11,11,11,11,11,11,12,12,12,12,13,13,13,13,14,14,14,15,15,15,15,16,17,17,18,19,27 Gears hung- 7,8,8,10,10,10,10,11,11,11,12,13,13,13,15,17,17,17,17, 18,19,19,20,21,21,2

    Sample Size for Stakeholders

    The chairman of the board wants to poll the stockholders to see what percentage are in favor of the policies of the current corporate president. How many shareholders must he survey if 20 percent are expected to return their questionaires and he wants to be within 2 percentage points of the percentage he would get if he were to

    Inferential tests

    I have been struggling with these questions for days now (see file attached). Can you please help? thanks. See attachment for full set of questions: 30. A retailer wants to obtain some current data on his customers' demographics (age, income, household size) and product preferences. He surveys all customers in his stor

    Acceptance Sampling

    An assembly line turns out 10% deffectives. Determine an acceptance number and sampling plan for samples of size 14 and a producers risk of 3%. (AQL = 10)). a) Based on the plan you devised in part a, determine the probability of still accepting if in reality the line is turning out 30% defectives. b) Determine an acceptance

    A union of restaurant and foodservice workers...

    A union of restaurant and foodservice workers would like to estimate the mean hourly wage, , of foodservice workers in the U.S. The union will choose a random sample of wages and then estimate using the mean of the sample. What is the minimum sample size needed in order for the union to be confident that its estimate is withi

    Suppose that we want to estimate the mean score on a nationwide examination...

    Suppose that we want to estimate the mean score on a nationwide examination in finance, and for this purpose we choose a random sample of exam scores. The sample we choose has a mean of and a standard deviation of . For each of the following sampling scenarios, determine which test statistic is appropriate to use when making i

    Sample space

    A campus organization will select one day of the week for an end of year picnic. Assume that the weekdays, Monday through Friday, are equally likely and that each weekend day, Saturday and Sunday, is twice as likely as a weekday to be selected. a) Assign probabilities to the seven outcomes. b) Find the probability a weekday

    Sample Space for Experiments

    Construct a sample space for each of the following experiments. a) Someone claims to be able to taste the difference between the same brand of bottled, tap, and canned draft beer. A glass of each is poured and given to the subject in an unknown order. The subject is asked to identify the contents of each glass. The number of

    Average Value of the Sample

    A soda distributor claims that a new display, featuring Lebron James will increase product sales in supermarkets by an average of 50 cases in a week. For a random sample of twenty supermarkets, the average sales increase was 41.3 cases, and varied across supermarkets by about 12.2 cases. What managerial conclusion can you draw

    Sampling techniques

    If you had to randomly choose 20 pages from a phone book what technique would be most suitable and why? 1.simple random sampling 2.stratified random sampling 3.systematic random sampling 4.cluster random sampling


    A random sample of 15 women yielded a mean pulse rate of 74.5 beats per minute, with a standard deviation of 9.6. A random sample of 12 men yielded a mean pulse rate of 76.0 beats per minute, with a standard deviation of 8.7. Test the claim that pulse rates for men and women are the same. Use a=.01.

    Test statistics

    The data below represents fields of specialization for the randomly selected sample of undergraduate students. Test to determine whether there is a significant difference in the fields of specialization between regions of the country. Use a=.05 Northeast Midwest south west Total Business 54

    Unusual Results - Interpreting Statistical Result

    A candy company claims that 92% of consumers like their candies. To test this claim, 9571 people are selected at random from those who have eaten the company's candies. 791 rate the candies as unsatisfactory. Is this an unusual result (show criterion for determining the answer to this question)? Also, how do you interpret your s