Statistical Analysis Flashcards
6 cards from real DA practice questions. Tap to flip, then mark Knew It or Still Learning โ missed cards come back until you master them.
Read the first 6 Statistical Analysis flashcards as text
What does a p-value less than 0.05 typically indicate in hypothesis testing?
Answer: The result is statistically significant
A p-value below 0.05 means there is less than a 5% probability the observed result occurred by chance, so we reject the null hypothesis.
Which measure of central tendency is most affected by extreme outliers?
Answer: Mean
The mean sums all values and divides by count, so extreme outliers pull it significantly in their direction.
What is the standard deviation a measure of?
Answer: Spread or dispersion around the mean
Standard deviation quantifies how much individual data points deviate from the mean on average.
A data analyst runs a t-test. What is the primary purpose of this test?
Answer: Compare means of two groups
A t-test is used to determine whether there is a statistically significant difference between the means of two groups.
What does a correlation coefficient of -0.9 indicate?
Answer: Strong negative relationship
A correlation of -0.9 is close to -1, indicating a strong inverse relationship where one variable increases as the other decreases.
Which statistical distribution is symmetric and bell-shaped?
Answer: Normal distribution
The normal distribution is symmetric around its mean and produces the familiar bell-shaped curve.