Vocabulary
This variable can take only two possible values.
What is a binary (dichotomous) variable?
In a density histogram, the total area always equals this amount.
What is 100%?
In this distribution, the mean equals the median.
What is a symmetric/normal distribution?
A z-score of 0 represents this location.
What is the mean?
If the variance is 49, what is the standard deviation?
What is 7?
This formula subtracts the mean from a raw score.
What is the deviation equation?
The area of a histogram bar is found by multiplying these two values.
What are height and width?
In a positively skewed distribution, the mean is ____ the median.
What is greater than?
If the mean is 70 and the SD is 5, what is the z-score for a score of 75?
What is 1?
Calculate the deviation for a score of 18 if the mean is 25.
What is -7?
This statistic is the average of the squared deviations.
What is the variance?
If a histogram bar has an area of 20% and a width of 5, what is its height?
What is 4% per unit?
Approximately what percentage of observations fall within ±2 SDs in a normal distribution?
What is 95%?
Approximately what percentile corresponds to a z-score of +1?
What is the 84th percentile?
A distribution has a mean of 50 and SD of 4. What raw score is 3 SDs above the mean?
What is 62?
This statistic measures the typical distance scores are from the mean.
What is the standard deviation?
A frequency histogram labels its y-axis with this quantity.
What is "# per unit"?
In a symmetric/normal distribution, the mean is located at this percentile.
What is the 50th percentile?
If the mean is 100 and the SD is 10, what raw score has a z-score of –2?
What is 80?
Scores are 10, 20, and 30. What is the mean?
What is 20?
These scores have a mean of 0 and a variance of 1.
What are z-scores?
A density histogram has three bars with areas of 25%, 30%, and 15%. What must the fourth bar’s area be?
What is 30%?
A distribution has a long tail extending toward smaller values. What type of distribution is it?
What is negatively skewed?
A student scored at the 97.5th percentile. Approximately what was their z-score?
What is +2?
A dataset has a mean of 40 and an SD of 6. A student has a z-score of 1.5. What is their raw score?
What is 49?