Probability
A coin is flipped twice. What is the probability of two heads? (Answer in fraction form)
1/4
A poll of 40 students finds 22 prefer online homework. What parameter is being estimated for the whole school? (Answer in a complete sentence)
the true population proportion of students who prefer online homework
What does a bar graph display? (Answer in a complete sentence)
categorical data is displayed
What does regression predict? (Answer in a complete sentence)
value of response variable using explanatory variable
What is a census? (Answer in a complete sentence)
data collected from entire population
A bag has 4 red and 6 blue marbles. One is picked. What is the probability it is blue? (Answer in fraction form simplified)
3/5
A sample mean is used to estimate a population mean. What is a parameter in this situation? (Answer in a complete sentence)
true population mean
What does a scatterplot show? (Answer in a complete sentence)
relationship between two quantitative variables
In ŷ = 5 + 2x what is the slope? (Answer as a number)
2
What is stratified sampling? (Answer in a complete sentence)
the population is divided into groups and random samples are taken from each group
A die is rolled. What is the probability of an even number? (Answer in fraction form simplified)
1/2
A p value is 0.03 in a test about students studying more than 2 hours per night. Alpha is 0.05. What decision is made? (Answer in complete sentence)
reject the null hypothesis since p < alpha
What does a positive correlation mean? (Answer in a complete sentence)
as one variable increases the other increases
A predicted value is 80 and actual is 75. What is the residual? (Answer as a number)
-5
What is selection bias? (Answer in a complete sentence)
when sample is not representative due to how it is chosen
A student guesses on 5 multiple choice questions with 4 choices each. What is the probability all are correct? (Answer in unsimplified exponential form)
(1/4)^5
A 95 percent confidence interval for average sleep is (6.2, 7.8). What does this mean? (Answer in a complete sentence interpretation)
we are 95 percent confident the true mean sleep time is between 6.2 and 7.8 hours
r = -0.60. Describe the relationship. (Answer in a complete sentence)
moderate negative linear relationship
What does r² = 0.50 mean? (Answer in a complete sentence)
50 percent of variation in y is explained by x
What is random assignment used for? (Answer in a complete sentence)
reduces confounding variables
Two cards are drawn without replacement from a 52 card deck. What is the probability both are red cards? (Answer in unsimplified fraction form)
(26/52)(25/51)
A school claims the average test score is 75. A 95 percent confidence interval is (72, 74). What does this suggest? (Answer in a complete sentence interpretation)
the claim is not supported because 75 is not in the interval
If Q1 = 8 and Q3 = 18, what is the IQR? (Answer as a number)
10
Why is a curved pattern a problem for linear regression? (Answer in a complete sentence)
linear model does not fit nonlinear relationship
What is the difference between experiment and observational study? (Answer in a complete sentence)
experiment imposes treatment observational study only observes