SAS Flashcards on Statistics

A sample from a population should be which of the following?

Which of the following is not a characteristic of predictive modeling?

The standard error measures the variability associated with the sample mean, x̄.

Select the statement below that incorrectly interprets a 95% confidence interval (15.02, 15.04) for the population mean, if the sample mean is 15.03 ounces.

How do you define the term power?

The location and spread of a normal distribution depend on the value of which two parameters?

What type of error did the bank manager make if he concluded that the loan error rate was above 1% when in reality it is not?

To reject a test with Student's t statistic, the t statistic should be far from 0 and have a small corresponding p-value.

Which PROC TTEST option would you use to change the confidence level in a confidence interval plot?

A CLASS statement is required in a two-sample t test.

You can examine Levene's test for homogeneity to more formally test which of the following assumptions?

Given the following output, is there sufficient evidence to reject the assumption of equal variances?

Given the following SAS output, is there sufficient evidence to reject the hypothesis of equal means?

Sample and Representativeness

A sample from a population must be representative to ensure accurate results in statistical analysis.

Predictive Modeling

Predictive modeling addresses relationships between variables, but does not simply answer "How is X related to Y?"

Standard Error

The standard error quantifies the variability associated with the sample mean (x̄); it reflects how much the sample mean would vary from the true population mean.

Confidence Intervals

Misinterpretation of a 95% confidence interval involves thinking there is a 0.95 probability that the true mean lies within the interval; this is incorrect.

Statistical Power

Power is defined as the measure of a statistical test's ability to correctly reject the null hypothesis when it is false, indicating the effectiveness of the test.

Normal Distribution Parameters

The location and spread of a normal distribution are determined by two parameters: the mean (μ) and the standard deviation (σ).

Type I Error

A Type I error occurs when a bank manager concludes that the loan error rate exceeds 1%, despite it being correct that it does not.

Student's t Test

To reject a null hypothesis in a t-test, the t-statistic must be significantly far from 0, accompanied by a small p-value.

PROC TTEST ALPHA Option

The ALPHA= option in PROC TTEST is used to adjust the confidence level for confidence interval plots.

CLASS Statement in T-tests

A CLASS statement is required when conducting a two-sample t-test to categorize the data properly.

Levene's Test for Homogeneity

Levene's test is used to formally evaluate the assumption of equal variances among groups in statistical analyses.

Evidence Against Equal Variances

Analysis from Levene's Test indicates insufficient evidence to reject the assumption of equal variances if the p-value is above the significance level (e.g., 0.05).

Hypothesis Testing with SAS Output

To determine whether there is enough evidence to reject the null hypothesis of equal means, analyze the F value and corresponding p-value from the provided SAS output.

Test your knowledge with these SAS flashcards focused on key statistical concepts. Challenge yourself with definitions, characteristics of predictive modeling, and interpretations of statistical measures. Perfect for students and professionals looking to reinforce their understanding of statistics using SAS.