Statistics

In a set of data, what is the median?

• The middle number when the data set is ordered
• The most frequently occurring number
• The difference between the highest and lowest numbers
• The average of all the numbers

What is the standard deviation?

• A measure of the amount of variation or dispersion in a set of values
• The maximum value minus the minimum value
• The square root of the variance
• The average distance from the mean

In a linear regression analysis, what does the slope of the regression line represent?

• The change in the dependent variable for a one unit increase in the independent variable
• The point where the line crosses the y-axis
• The average value of the independent variable
• The maximum value of the dependent variable

What is a Type I error in hypothesis testing?

• Rejecting a true null hypothesis
• Rejecting a false alternative hypothesis
• Accepting a true alternative hypothesis
• Accepting a false null hypothesis

What does a p-value less than 0.05 typically indicate in hypothesis testing?

• There is strong evidence against the null hypothesis
• There is a 5% probability that the observed data occurred by chance
• The sample size is too small
• The null hypothesis is definitely true

What is the purpose of a confidence interval in statistics?

• To estimate the range within which a population parameter lies with a certain level of confidence
• To calculate the exact value of a population parameter
• To determine if a data set is normally distributed
• To test the null hypothesis directly

Which of the following measures of central tendency is most affected by extreme values or outliers?

• Mean
• Range
• Mode
• Median

Which statistical test is most appropriate for comparing the means of two independent samples?

• Independent samples t-test
• Paired samples t-test
• One-sample t-test
• Chi-squared test

What does the R-squared value in a linear regression analysis indicate?

• The proportion of the variance in the dependent variable that is predictable from the independent variable(s)
• The slope of the regression line
• The mean of the dependent variable
• The correlation between the independent and dependent variables

In the context of a normal distribution curve, what does the term 'standard deviation' signify?

• The distance from the mean to the point where the curve changes concavity
• The total area under the curve
• The average value of all the data points
• The peak height of the curve