A Chi-square test is used to:
Analyze the variance within and between groups.
Analyze the relationship between two categorical variables.
Determine if a sample mean is significantly different from a known population mean.
Compare the means of two groups.
In simple linear regression, what does a negative slope of the regression line indicate?
There is no relationship between the independent and dependent variables.
As the independent variable increases, the dependent variable increases.
As the independent variable increases, the dependent variable decreases.
The relationship between the independent and dependent variables is non-linear.
A coin is flipped 5 times. What is the probability of getting exactly 3 heads?
0.6875
0.25
0.5
0.3125
What is the range of the Pearson correlation coefficient?
0 to infinity
-1 to 1
0 to 1
-1 to 0
A high R² value in a regression analysis always indicates a good fit of the model. Is this statement true or false?
False
True
When is it appropriate to use a one-tailed hypothesis test?
When the sample size is small.
When you are only interested in detecting a difference in one direction.
When the data is not normally distributed.
When you want to test for a difference in either direction.
As the sample size increases, the standard error of the mean:
Decreases
Increases
Stays the same
Cannot be determined
A bag contains 3 red balls and 2 blue balls. You draw two balls from the bag without replacement. What is the probability that the second ball is red, given that the first ball was blue?
1/4
3/4
2/5
3/5
Which of the following is NOT an assumption of linear regression?
Independence of observations
Normality of the independent variable
Linearity of the relationship between independent and dependent variables
Homoscedasticity (equal variance of errors)
If the variance of a random variable is 9, what is its standard deviation?
18
81
3
9