Exam 3: Reasoning From Sample to Population

Suppose you send out 350 surveys to random sample of all past customers (your target population) asking them to report their level of satisfaction with your product. Of the 350, you used the 112 that responded to the survey to construct a confidence interval for the population "satisfaction score." What might be a potential problem with this confidence interval?

The step that requires the use of inductive reasoning when making an active prediction from a sample of data is:

When calculating the sample variance of a random sample, you divide the sum of the squared deviations (from the sample mean) by N - 1 instead of N to ensure the estimator achieves what property?

Suppose you have a random sample of 2,179 credit scores from a population of mortgage applicants with a sample mean of 620 and sample standard deviation of 70, and would like to determine if this is sufficient enough to rule out that the population mean is not 610. Which of the following objects would you calculate to make this decision?

Which sample statistic is going to dictate the center of a confidence interval for the population mean?

In making active predictions based on sample data it requires the use of what sort of reasoning?

In evaluating the credibility of a null hypothesis, it is standard to construct a single value derived from the sample which is known as the:

Over many trials, the 99% confidence interval will not include the true population parameter what percent of the time?

Which of the following are you assuming is true to calculate the p-value of a test statistic?

To conduct a hypothesis test at the 95% percent confidence interval the maximum p-value that you would be willing to (accept) fail to reject the null hypothesis would be?

The probability of attaining a test statistic at least as extreme as the one that was observed is known as the:

Suppose you have a random sample of 200 students' GMAT scores that have a sample mean of 700 and sample standard deviation of 50, and would like to calculate the 90 percent confidence interval of the population mean. Which of the following would be the correct construction?

If one is attempting to make a prediction on how much sales will increase in the event of a price discount of 10%, which step will not use deductive reasoning in conducting the prediction?

For a given set of sample statistics, changing the null hypothesized value (K) for a population mean changes everything except for what?

If the t-stat for a hypothesis test (with a two-sided alternative) comes back as 2.6, what would be the appropriate conclusion to draw regarding the null hypothesis under a 95% confidence level?

Suppose you have a random sample of employees in your company and their tenure. The sample mean of this sample is 4.2 years and the sample standard deviation is 4.5 years. How would knowing that the random sample was of size 100 instead of 60 change the p-value of the hypothesis test?

Suppose you have a random sample of 2179 credit scores from a population of mortgage applicants with a sample mean of 620 and known population standard deviation of 70, and would like to calculate the 99% confidence interval of the population mean credit score. Which of the following would be the correct construction?

An unbiased estimator achieves what sort of property?

Suppose a sample of five econometrics students' heights were: 69 inches, 73 inches, 65 inches, 67 inches, and 71 inches. The standard deviation of the heights will be in what units?

Can a t-stat be negative for the hypothesis test of the population mean of the heights of econometrics students (which will always be positive)?