Shift and Scale
Adding 5 to the mean of a distribution would change the median by this value.
What is 5?
This percentile is the value below which 50% of the data fall.
What is the 50th percentile?
The Z-score tells how many "______" the observed value is from the mean.
What is standard deviation?
In any density curve, this is always the total area under the curve.
What is 1?
A normal model is called a normal model because its values are ___
What is normally distributed?
A teacher records the quiz scores (out of 10 points) for a class and then decides to adjust all the scores by adding 2 points to each student’s original score. What statistic of the test scores will increase?
What is the center?
This term is used to describe the range between the 25th and 75th percentile.
What is IQR?
If you have a sample mean of 20, observed mean of 10, and a SD of 5 in a given distribution, this would be the z-score.
What is -2?
If the distribution is approximately normally distribute, this is the measure of variation we should use.
What is standard deviation?
What is the notation used for a normal model to describe mean and SD?
What is N(mean, standard deviation)?
If we have a set of values and we add or subtract from the original values, the shape will look ____
What is the same?
True or False. If we add or subtract a constant to the original values of a dataset, the percentile will change.
What is False?
A student scores 82 on a test with a mean of 75 and a standard deviation of 5. What is the z-score?
What is 1.4?
If the distribution is skewed, this is the measure of center we should use.
What is the median?
These are all three major percentages in the normal model (also known as the empirical rule).
What is 68%, 95%, and 99.7%?
This type of transformation changes both the center and spread of a distribution.
What is multiplying or dividing by a constant?
If Bob scored a 65 on the test, what percentile is he in?
What is the 50th percentile?
The heights of adult women in a population are approximately normally distributed with a mean of 64 inches and a standard deviation of 2.5 inches. A woman who is 68 inches tall will yield a z-score of -1.6. This means the woman is 1.6 standard deviations _____ the mean.
What is below?
This is the point that divides the area under the curve in half.
What is the median?
In a normal model, this is the percentage of the distribution that lies outside of 3 standard deviations.
What is 0.03%?
If we increase the salaries in a dataset by 6% and add $2000 for each employee, the spread will be multiplied by this constant.
What is 1.06?
A high school administered a standardized math test to 500 students. The scores were approximately normally distributed with a mean of 72 and a standard deviation of 8. How many students scored above the 80th percentile?
What is 100?
Assume test scores are normally distributed with a mean of 75 and a standard deviation of 10. This is percentage of students that scored above 85.
This term refers to a curve where the mean, median, and mode are the same.
What is a normal density curve?
Suppose a normal model describes fuel efficiency of cars in Idaho. The mean is 24 mpg, with a SD of 6 mpg. This is the percentage of cars in Idaho with fuel efficiency less than 15 mpg.
What is 6.68%?