All Flashcards
Explain the concept of symmetry in a distribution.
A distribution is symmetric if it can be folded in half, and both sides look like mirror images. Symmetrical data often has the mean and median close together.
Explain the concept of skewness in a distribution.
Skewness refers to the asymmetry of a distribution. A right-skewed distribution has a longer tail on the right, while a left-skewed distribution has a longer tail on the left. Skewness affects the relationship between the mean and median.
Explain the concept of standard deviation.
Standard deviation measures the typical distance of data points from the mean. It indicates how spread out the data is around the average value. Best for symmetric distributions.
Explain why the median is resistant to outliers.
The median is the middle value in a dataset. Outliers, being extreme values, do not affect the position of the middle value as much as they affect the mean, which is calculated using all values.
Explain why it is important to investigate outliers.
Outliers might be valid but unusual data points. Discarding them without investigation may lead to a loss of important information or a misunderstanding of the data.
Explain the importance of context when describing a distribution.
Relating your answer back to what the data represents provides a meaningful interpretation of the distribution. It connects the statistical description to the real-world scenario.
What is the formula for Range?
Range = Maximum value - Minimum value
What is the formula for Interquartile Range (IQR)?
IQR = Q3 - Q1
How do you calculate the mean?
Sum of all values divided by the number of values.
How do you calculate the median?
The middle value when the data is ordered from least to greatest.
How to identify outliers?
Values significantly higher or lower than the rest of the data.
What is a symmetric distribution?
A distribution where both sides look like mirror images when folded in half.
What is a right-skewed distribution?
A distribution with a tail longer on the right side; mean > median.
What is a left-skewed distribution?
A distribution with a tail longer on the left side; mean < median.
What is a mode in a distribution?
The most frequent value(s) in a dataset, represented by peak(s) in a histogram.
What are outliers?
Values that are significantly higher or lower than the rest of the data.
What is the range of a dataset?
Maximum value minus the minimum value.
What is the Interquartile Range (IQR)?
The range of the middle 50% of the data (Q3 - Q1).