In ANOVA, what does the F-statistic represent?
The ratio of between-group variance to within-group variance.
The correlation coefficient between the independent and dependent variables.
The difference between the smallest and largest group means.
The probability of observing the data if all group means were equal.
Which of the following smoothing methods is most appropriate when the time series data exhibits a trend but no seasonality?
Double Exponential Smoothing
Moving Average Smoothing
Simple Exponential Smoothing
Triple Exponential Smoothing
A Chi-square test is used to:
Compare the means of two groups.
Determine if a sample mean is significantly different from a known population mean.
Analyze the variance within and between groups.
Analyze the relationship between two categorical variables.
In residual analysis, what does a pattern in the residuals plot indicate?
The relationship between the variables may not be linear.
The linear model is a good fit for the data.
There is no correlation between the variables.
The errors have constant variance.
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
3/5
2/5
3/4
What does a Pearson correlation coefficient of -0.9 suggest about the relationship between two variables?
Weak positive linear relationship
Strong negative linear relationship
No linear relationship
Strong positive linear relationship
In exponential smoothing, a higher value of the smoothing parameter (alpha) gives _______ weight to recent observations.
Equal
Zero
Higher
Lower
Which of the following is an example of a non-parametric inferential statistical test?
t-test
z-test
ANOVA
Chi-square test
An autoregressive model (AR) uses ______ values of the time series to predict future values.
Average
Past
Future
Random
As the sample size increases, the standard error of the mean:
Stays the same
Cannot be determined
Increases
Decreases