1-var Quant. Data
Graphs that show distribution shape and are useful for large datasets. Graphs that show spread and outliers and are good for comparisons.
What are histograms and boxplots?
These three characteristics describe a distribution in terms of its symmetry, typical value, and variability.
What are shape, center, and spread?
Bias that occurs when people choose whether to participate, often seen in online polls.
What is voluntary response bias?
This is the probability of flipping heads on a fair coin.
What is 0.5?
13 represents this type of measurement of center.
5, 8, 9, 13, 15, 17, 21.
What is the median?
These two summary statistics are not affected by outliers because they ignore extreme values.
What are the median and interquartile range (IQR)?
This occurs when a portion of the population is left out of the sampling process.
What is undercoverage?
The chance of randomly drawing an ace from a standard deck of 52 cards.
What is 4 out of 52, or 1/13, or approximately 0.077?
The mean increases but the standard deviation stays the same.
What happens when you add a value to a dataset?
In a normal distribution with a mean of 20 and standard deviation of 3, most values fall in this range.
What is the interval from 14 to 26?
A method to reduce sampling bias by giving every member of the population a known chance of selection.
What is random sampling (such as SRS or stratified sampling)?
The probability of both A and B occurring, if P(A) = 0.3 and P(B) = 0.4 and the events are independent.
What is 0.3 × 0.4 = 0.12?
These values lie beyond Q1 − 1.5×IQR or above Q3 + 1.5×IQR.
What are outliers as identified by the 1.5×IQR rule?
In a left-skewed distribution, this measure of center is greater than the other; in a symmetric distribution, they are approximately equal.
What is the median being greater than the mean in left-skewed distributions, and mean ≈ median in symmetric distributions?
This type of sampling may lead to unreliable results because it overrepresents easily accessible individuals.
What is convenience sampling?
When rolling two dice, the probability that their sum equals 7.
What is 6 out of 36, or 1/6?
This is true about the mean and median when a distribution is skewed to the right.
What is the mean being greater than the median?
This measure of center is more appropriate for a distribution that is skewed right with outliers.
What is the median?
A sampling method where every 10th person on a list is selected; it is efficient but may miss patterns in the data.
What is systematic sampling?
The probability of getting exactly 2 heads in 3 coin tosses.
What is C(3,2) × (0.5)³ = 3 × 0.125 = 0.375?