4. Probability

Suppose a normal distribution has mean $\mu$ and standard deviation $\sigma$. According to the empirical rule, what is the approximate probability that a randomly selected value from this distribution falls within one standard deviation of the mean (that is, between $\mu -\sigma$ and $\mu +\sigma$)?

If you toss a fair coin $20$ times, what is the probability that it lands on tails in a single toss?

In the context of basic concepts of probability, how do scientists use $probability$ when describing risks?

Suppose the error involved in making a certain measurement is a continuous random variable $x$ with cumulative distribution function (cdf) $F\left(x\right)=\{\begin{array}{cc}0& ,x<0\\ \frac{x}{2}& ,0\le x<2\\ 1& ,x\ge 2\end{array}$. What is the probability that the error is less than 1.5?

In the context of quality control, which probability distribution is most commonly used to calculate the probability of producing a defect in a single trial?

In the context of probability and statistics, which of the following best describes what it means for two variables to be positively associated and negatively associated?

Which of the following research questions would not be tested using inferential statistics?

Which of the following expressions represent the same probability value as $\frac{1}{4}$?

If $18$ out of $30$ students in a class passed an exam, what is the probability that a randomly selected student from this class passed the exam? Express your answer as a simplified fraction.

Which of the following correctly represents the formula for the probability of the union of two events $A$ and $B$ in probability theory?

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

In the context of probability, how is a $\mathrm{sample}$ related to a $\mathrm{population}$?

If the chosen significance level is $\alpha$ = $0.05$, then there is a 5% chance of which of the following?

Which characteristic must be known about a data set before the empirical rule can be applied?

A florist has $5$ roses, $3$ tulips, and $2$ daisies in a basket. If one flower is selected at random for a bouquet, what is the probability that the selected flower is a tulip?