Unit 6: One-Variable Stats
These are the three points that divide a data set into four equal groups
What are Quartiles
This symmetrical, bell-shaped distribution has a mean, median, and mode that are all equal
What is the Normal Distribution
This type of linear correlation exists when the pattern in a scatter plot slopes up to the right
What is Positive Correlation
If the probability of an event P(A) is 0.4, what are the "odds against" that event occurring?
3:2
What is the result of evaluating the factorial expression 100!/98!
9,900 (100×99)
This measure of spread is calculated as Q3−Q1 and contains the middle 50% of the data
What is the Interquartile Range (IQR)
Approximately what percentage of the data falls within 3 standard deviations from the mean?
What is 68%
This term refers to making a prediction beyond the given data points in a set
What is Extrapolation
Using the formula P(n,r), how many ways can a club of 15 members select a President, Vice President, and Treasurer?
2,730 (15×14×13)
If time to eat a doughnut is uniformly distributed from 0.5 to 3 minutes, what is the probability a customer takes between 1 and 3 minutes?
0.8 or 80%
Area = base × height; (3−1)×3−0.51=2/2.5
This value represents the average distance of the data scores from the mean
What is Standard Deviation
This term refers to the probability that a statistic is within the interval indicated by the margin of error
What is the Confidence Level
This value (r), ranging from -1 to 1, indicates the strength and direction of a linear relationship
What is the Correlation Coefficient
How many ways are there to select 3 students to be class representatives from a class of 30 students?
4,060 (Calculated as (30C3))
For a binomial distribution where the probability of success is 0.72, what is the expected number of wins in an 82-game season?
59.04 wins (Formula np=82×0.72)
This formula, z=(x−xˉ)/σ, calculates the number of standard deviations an observation is from the mean
What is a z-score
To approximate a binomial distribution with a normal one, these two conditions must be met regarding np and nq
What is "both are greater than 5"
This is the difference between an actual data point's value and the value predicted by the line of best fit
What is a Residual
If the mean is 75 and the standard deviation is 10, what is the calculated z-score for an observation of 85?
1 (z=(85−75)/10)
According to the patterns in Pascal’s Triangle, what is the sum of all numbers in the 8th row (n=8)?
256 (Formula 2n=28)
A data point is formally defined as one of these if it is more than 1.5 times the IQR below Q1 or above Q3
What is an Outlier
This must be used when approximating a discrete distribution with a continuous one, such as using an interval of 4.5 to 5.5 to represent exactly 5
What is a Continuity Correction
This specific linear model is fit to a data set using medians calculated from three vertical sections of a scatter plot
What is a Median-Median Line
In a game where you win $1.50 for two heads, $0.50 for one head/one tail, and lose $2.00 for two tails, what is the expected value (E(x))?
$0.125 (or12.5cents)
(0.25(1.50) + 0.50(0.50) + 0.25(-2.00))
Using the margin of error formula for 1000 people with 40% support (p=0.4) at 95% confidence (z=1.96), what is the calculated margin of error?
3.03% (or 0.0303)
1.96 X sqrt((0.4*0.6)/1000)