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Statistics Questions and Answers

Can you please begin to explain to me the difference between how concepts are measured and a variable in social sciences research? What is the difference between a variable and a concept. The homework assignment entailed. gathering 3 topics of interst from the General Social Survey. (I selected Death Penalty, Education, Race) would each of these items be considered the variable? and how would I go about measuring each concept? Are these items concepts or variables?

Which of the following is NOT true about forecasting? It is good practice to include a measure of expected forecast error with any forecast. In exponential smoothing, a lower smoothing constant will better forecast demand for a product experiencing high growth. It is good practice to use more than one forecasting model and then take a look at the results using common sense. A benefit of qualitative forecasts is that they take advantage of expert opinion.

Why is an expanded concept of variation necessary in statistical improvement? Is all variation necessarily numerical? How might this approach invalidate concepts and techniques taught in traditional basic statistics courses?

Would statistics on the political affiliation of members of a local church be an example of nominal, ordinal, interval or ratio level of measurement?

Why is the analysis of statistic sometimes considered an art?

What are the most important aspects of validity for the tester? give anser in points

How do you deal with response rate, missing data, and the errors they create?

When forecasting using moving average, if you use a shorter number of periods to calculating the moving average, it will more closely follow the trends than if you use a larger number of periods. True or False? 

When using statistical evidence, why is it important that it was compiled by a disinterested source?

A researcher has collected two samples of data, and the sample variances are 2.16² and 4.82². It would be appropriate to use the two-sample t-test with a common variance.

A politician is concerned with winning an upcoming election.  What null hypothesis is he testing if he commits a Type l error when he says that he will win the election?

A U.S. travel center survey reported that Americans stayed an average of 7.5 nights when they went on vacation. The sample size is 1500. Find a point estimate of the population mean. Find the 95% confidence interval of the true mean. Assume the population standard deviation was 0.8.

Can you tell me which of the following is an example of a true negative outcome? 1. Mary's pregnancy test came back negative, but she is actually pregnant 2. Joe's car was clocked speeding by a radar gun while he was going faster than the posted speed limit 3. Anna failed an exam because she hadn't learned the information it covered 4. Tony's strep test came back negative, but he didn't recover without antibiotic treatment

Find the mean from the following chart: class              frequency 31-33                 18 34-36                 18 37-39                 10 40-42                15 43-45                 5

When is a type 1 error made?

How can it be explained that causal statements cannot be made from correlational data? This is about correlation in Statistics.