Variables
Takes a wide range of values and it is sensible to add, subtract, or take averages with those values.
What is a numerical variable?
Sampling method in which each case in the population has an equal chance of being included and there is no implied connection between the cases in the sample.
What is a simple random sample?
Two events that cannot both happen.
What is disjoint/mutually exclusive?
Represents the probability of observing data as extreme as or more extreme than what was observed, assuming the null hypothesis is true.
What is a p-value?
b_1 in the equation: hat_y = b_0 + b_1x.
What is the slope?
A variable that might causally affect another.
What is an explanatory variable?
The percentage that fits the following question: "If Q1 = 8% and Q3 = 14%, what is the IQR?"
What is 6%?
Number that answers the following question: "What is the probability of rolling a 1 or a 2 on a fair-sided die?"
What is 1/3?
Construct a 95% confidence interval for p, the proportion of NY adults who supported a quarantine for anyone who has come into contact with an Ebola patient. Let SE = 0.012 and hat_p = 0.82. Round to three decimals.
What is (0.796, 0.844)?
R = -1
What is the strongest negative linear relationship between two numerical variables?
The random variable that is used to describe the number of successes in a fixed number of trials.
What is the binomial RV?
Sampling method that matches the following example: A political survey is done by stopping people walking in the Bronx.
Number that answers the following question: "If P(A) = 0.2, P(A and B) = 0.1, and P(A or B) = 0.4, what is P(B)?"
What is 0.3?
Number that answers the following: "Assume that we surveyed 200 people and asked them their shoe size and found a sample mean of 9 with a sample standard deviation of 0.5. Assume that the "claimed" mean for shoe size is 9.5. What is the T-score of our sample mean?"
What is -14.14?
Given that the point (101780, 19940) is on the line and the slope estimate b_1 = -0.0431, this is the value of b_0.
What is 24,327?
An individual trial that has only two possible outcomes, often labeled as a success or failure.
What is a Bernoulli random variable?
A data set in which the mean is less than the median.
What is skewed left?
Formula for the conditional probability of outcome A given condition B.
What is P(A|B) = P(A and B)/P(B)?
Error made when H_0 is true, but we reject H_0 in favor of H_A.
What is a Type 1 Error?
Suppose that we are given the following regression line predicting financial aid based on family income: hat_y =24327 - 0.0431x. Please provide an interpretation of the intercept.
What is "the average financial aid if a family has no income is $24,327"?
What is 1.1?
Number the answers the following question: "Consider a contingency table with homeownership (rent/mortgage/own) in the first row and application type (individual/joint) being the first column. If the number of individuals who rent is 3496, the number of overall renters is 3858, and the number of total individuals is 8505, what is the row proportion for individual/rent?"
What is 3496/8505 = 0.411?
Number that answers the following question: "Consider flipping a fair coin, what is the probability that the first heads occurs on the third trial?"
What is 0.125?
Number that answers the following question: "A market researcher wants to evaluate car insurance savings at a competing company. Based on past studies, they are assuming that the standard deviation of savings is $100. They want to collect data so that they can get a margin of error of no more than $10 at a 95% confidence level. How large of a sample should they collect?"
What is 385?
Suppose that we are given the following regression line predicting price based on whether a video game is new or used: hat_price = 42.87 + 10.90*cond_new where cond_new = 0 if the game is used and cond_new = 1 if the game is new. Interpret the slope of this line.
On average, new games sell for about $10.90 more than used games.