4. Probability

Which of the following is a proper way to describe the probability of flipping heads on a fair coin?

How many different simple random samples of size $3$ can be selected from a population of size $7$?

Suppose Richard is taking a multiple-choice test with $10$ questions, each with $4$ answer choices, and he guesses randomly on each question. What is the probability that Richard will answer at least half of the questions correctly?

Which of the following statements is most accurate when defining $percentiles$ in probability and statistics?

Assume that we have two events, $A$ and $B$, that are mutually exclusive. Assume further that we know $P\left(A\right)$ and $P\left(B\right)$. What is $P\left(A\cup B\right)$?

In the context of probability and statistics, primary data consist of □.

Given that $x$ has a Poisson distribution with parameter $\lambda$, which of the following is the correct expression for the probability that $x$ equals $k$?

Given the following probabilities: $p\left(a\right)=0.3$, $p\left(b\right)=0.2$, and $p(a\wedge b)=0.4$, which of the following statements is true?

Suppose the probability that Mountain View gets at least $4$ inches of rain in a month is $0.25$. What percent of the time did Mountain View get at least $4$ inches of rain in a month?

Which of the following are valid ways of expressing probability? Select one option.

Which of the following best represents an empirical probability?

Which of the following scenarios fits the condition of a $Bernoulli$ process?

Which of the following is not a property of the t distribution?

Suppose a baseball team has $10$ players, $3$ of whom have a batting average under $300$. If one player is selected at random, what is the probability that the player has an average under $300$?

Which of the following statements correctly verifies that the function $p\left(x\right)=\frac{1}{4}$ for $x=1$, $x=2$, $x=3$, $x=4$ and $p\left(x\right)=0$ otherwise is a probability mass function?