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Hypothesis Testing

Inference in the Yellow Pages Effect

To determine the effect of advertising in the Yellow Pages, Bell Telephone took a sample of 40 retail stores that did not advertise in the Yellow Pages last year but did so this year. The annual sales(in thousands of dollars) for each store in both years were recorded and stored in file yellow pages a. Estimate with 90% confide

Inference

One factor in low productivity is the amount of time wasted by workers. Wasted time includes time spent cleaning up mistakes, waiting for more material and equipment, and performing any other activity not related to production. In a project designed to examine the problem, an operations management consultant took a survey of 200

T stats

The American Medical Association conducts surveys of its members each year. A sample of physicians is selected and asked to report the amount of time each devotes to patient care each week. The results for the survey are stored in the excel file. Can we infer that the mean amount of time devoted to patient care per week by all p

restaurant site is acceptable based on pedestrian traffic.

A fast food franchiser is considering building a restaurant at a certain location. Based on financial analyses, a site is acceptable only if the number of pedestrian passing the location averages more than 100 per hour. The number of pedestrians observed for each of 40 hours was recorded and stored in the attached excel file .

Z-estimate

In an attempt to reduce the number of person-hours lost as a result of industrial accidents, a large production plant installed new safety equipment. In a test of the effectiveness of the equipment, a random sample of 50 departments was chosen. The number of person-hours lost in the month prior to and the month after the install

Expectation and Hypothesis Testing

4. An experiment is set to test the hypothesis that a given coin is unbiased. The decision rule is the following: Accept the hypothesis if the number of heads in a sample of 200 tosses is between 90 and 110 inclusive, otherwise reject the hypothesis. a) Find the probability of accepting the hypothesis when it is correct.

Statistics problems

Please explain fully, using Excel when necesary. These questions were addressed once already, but they were not explained in a way in which they could be fully understood. Please detail each step. Thanks! 1)A publisher is considering three different covers for a new magazine. A random sample of 90 people are asked to pick the

Statistics problems

Please use Excel when necessary: 1) When the p-value is smaller than the significance level: a) A type 1 error is committed b) A type 11 error is committed c) The null hypothesis is rejected d) The critical value is correct. Problem # 2) The coefficient of correlation between the variables X and Y was computed to be -0.6

That there are no differences between the two groups of subjects

A) Analyse the data below to test the hypotheses that there are no differences between the two groups of subjects in terms of their walking time to exhaustion (in seconds) and ratings of perceived exertion (RPE) after 8 minutes of walking. Healthy subjects --------------------------------------------------------------------

Sample proportion hypotheses test

Ho: P<= .7 Ha: P > .7 Sample Data Set: 300 Sample Proportion of .853 What is the standard error of the proportion? What is the z-test? How do you compute the p value? What do you do with the Ho?

Biopstatistics Problem

I hope you can help me with this problem. I have 2 questions regarding this study. 1) I have heard from my teacher that there is a 7th null hypothesis hidden in the text for this study. The first 6 are presented in the tables. WHAT IS THE 7TH NULL HYPOTHESIS??? They are: Ho1: Cr 3+and As3+ has no effect on glucose to

Using Spearman's - Is my data statistically significant?

Hi there, I used excel to analyze my data with spearmans rank order co efficient test and came up with the attached table. I have a query about finding out whether my correlation coefficient - 0.420- is statistically significant. This is what i understand (not much!) - take the t value and compare it to the critical val

Statistics Problem

Can you tell me how you would do the attached problem? My idea is to take the difference of Day 0 and Day 365 (using the absolute value of it) then use ANOVA. Does that make sense?

What you need to know about null hypothesis?

Here is the scenario: Suppose we hypothesize that there is a negative (inverse) relationship between treatment and depression. We'd like to test this hypothesis, so we obtain two samples. Sample 1 is drawn from a population of depressed persons who have not received any type of treatment. Sample 2 is drawn from a population o

Statistics question

A researcher hypothesizes that the lowering in cholesterol associated with weight loss is really due to exercise. To test this, the researcher carefully controls for exercise while comparing the cholesterol levels of a group of subjects who lose weight dieting with a control group that does not diet. The difference in mean chole

Hypothesis Testing: Average Speed

Question: Suppose a candidate running for sheriff claims that she will reduce the average speed of emergency response to less than 30 minutes. (30 minutes is thought to be the average response time with the current sheriff.) There are no past records, so the actual standard deviation of such response times cannot be determined.

Correlation coefficient

Please show the prcoess to work the following problems. I do not understand this area at all. Thank you for your assistaance.

Critical Values

Find the left and right critical values from the appropriate table for a 95% confidence interval for the mean when the sample size is 23.

Stats

A real estate agent wishes to see if there is a difference in appraisal values given to homes by real estate appraisers and by tax assessors. Real Estate Appraisers Tax Assessors Means $83,256 $88,354 S $ 3,142 $ 2,341 N 15 15 Find the test value. ONLY!!! In testing for a dif

Hypothesis Testing - decision making situations

Consider some decision-making situations in Business Management field of study, and describe two or more in which tests of one or more population variances are important. Use Internet resources to provide examples of situations in which population variance tests were performed. Be sure to include the url address where you found

Hypothesis Testing for Samples

You are the manager of a factory that produces Mini-Oats Cereal. The factory has an automated packaging machine that can be set at any targeted fill level between 12 and 32 ounces. Every box of cereal is not expected to contain exactly the targeted weight, but the average of all boxes filled should. At the end of every shift (8

For OTA 103997 only

Only for above listed OTA. Find the margin of error E: Grade point averages, 99% confidence, n= 75, mean = 2.76, s= 0.88

Critical Value and Decision

In an experiment to determine the effect of nutrition on the attention spans of elementary school students, a group of 15 students were randomly assignment to each of three meal plans: no breakfast, light breakfast, and full breakfast. Their attentions spans (in minutes) were recorded during a morning reading period and are sho

Testing

He U.S. Bureau of Prisons publishes data in Statistics Report on the times served by prisoners released from federal institutions for the first time. Independent random samples of released prisoners in the fraud and firearms offense categories yielded the following information on time served in months. Mean s n Samp