c. α
d. 1 – α
e. α = 0.05
Which of the following is not required in a binomial setting?
a. Each trial is considered either a success or a failure.
b. Each trial is independent.
c. The value of the random variable of interest is the number of trials until the first success occurs.
d. There is a fixed number of trials.
e. Each trial succeeds or fails with the same probability.
X and Y are independent random variables with μ (^) X = 3.5, μ (^) Y = 2.7, σ (^) X = 0.8, and σ (^) Y = 0.65. What
are μ (^) X +Y and σ (^) X +Y?
a. μ (^) X +Y = 6.2, σ (^) X +Y = 1.03
b. μ (^) X +Y = 6.2, σ (^) X +Y = 1.0625
c. μ (^) X +Y = 3.1, σ (^) X +Y = 0.725
d. μ (^) X +Y = 6.2, σ (^) X +Y = 1.45
e. μ (^) X +Y = 6.2, σ (^) X +Y cannot be determined from the information given.
A researcher is hoping to find a predictive linear relationship between the explanatory and response
variables in her study. Accordingly, as part of her analysis she plans to generate a 95% confidence
interval for the slope of the regression line for the two variables. The interval is determined to be
(0.45, 0.80). Which of the following is (are) true? (Assume conditions for inference are met.)
I. She has good evidence of a linear relationship between the variables.
II. It is likely that there is a non-zero correlation (r ) between the two variables.
III. It is likely that the true slope of the regression line is 0.
a. I and II only
b. I and III only
c. II and III only
d. I only
e. II only
In the casino game of roulette, there are 38 slots for a ball to drop into when it is rolled around the
rim of a revolving wheel: 18 red, 18 black, and 2 green. What is the probability that the first time a
ball drops into the red slot is on the 8th trial (in other words, suppose you are betting on red every
time—what is the probability of losing 7 straight times before you win the first time)?
a. 0.0278
b. 0.0112
c. 0.0053
d. 0.0101
e. 0.0039
You are developing a new strain of strawberries (say, Type X) and are interested in its sweetness as
compared to another strain (say, Type Y). You have four plots of land, call them A, B, C, and D,
which are roughly four squares in one large plot for your study (see the figure below). A river runs