DAC Statistical Methods & Analytics Flashcards
6 cards from real DAC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 DAC Statistical Methods & Analytics flashcards as text
What does the term 'mean' refer to in descriptive statistics?
Answer: The arithmetic average of all values
The mean is calculated by summing all data values and dividing by the count of values, giving the arithmetic average.
Which measure of central tendency is most resistant to the influence of extreme outliers?
Answer: Median
The median, being the middle value of a sorted dataset, is not affected by extreme outliers the way the mean is.
In hypothesis testing, what does a p-value less than 0.05 typically indicate?
Answer: There is statistically significant evidence to reject the null hypothesis
A p-value below the significance threshold (commonly 0.05) indicates the observed results are unlikely under the null hypothesis, supporting its rejection.
What does standard deviation measure in a dataset?
Answer: The average distance of data points from the mean
Standard deviation quantifies how spread out the data values are around the mean — a larger value indicates more variability.
Which type of correlation coefficient is used to measure the linear relationship between two continuous variables?
Answer: Pearson's r
Pearson's r measures the strength and direction of the linear relationship between two continuous, normally distributed variables.
What is the purpose of a confidence interval in statistical analysis?
Answer: To provide a range of values likely to contain the true population parameter
A confidence interval gives a range of plausible values for a population parameter, with a specified level of confidence (e.g., 95%).