4. Probability

In the context of basic probability and statistics, which two of the following are considered primary sources of data?

Suppose the probability that it rains on a given day is $0.3$. What is the probability that it does not rain on that day?

"[DATA] A Random Process: Green Lights On your drives to school each day you feel like there is a light that is always red when you reach it. You decide to record data to determine the likelihood of arriving at the light while it is red. Open the data set 5_1_38 at www.pearsonhighered.com/sullivanstats, which contains the day number and whether the light was red (1), or not (0), for 120 consecutive days in which you drove to school.

f. What is the estimate of the probability of the light being red when you reach the intersection?"

Gestation Period versus Weight The following data represent the birth weights (in grams) of babies born in 2017, along with the period of gestation.

b. What is the probability that a randomly selected baby born in 2017 weighed between 3000 and 3999 grams?

Lottery. In Exercises 15–20, refer to the accompanying table, which describes probabilities for the California Daily 4 lottery. The player selects four digits with repetition allowed, and the random variable x is the number of digits that match those in the same order that they are drawn (for a “straight” bet).

Using Probabilities for Significant Events

a. Find the probability of getting exactly 3 matches.

Using a Tree Diagram In Exercises 67-70, a probability experiment consists of rolling a six-sided die and spinning the spinner shown at the left. The spinner is equally likely to land on each color. Use a tree diagram to find the probability of the event. Then explain whether the event can be considered unusual.

68. Event B: rolling an odd number and the spinner landing on green

Favorite Day to Order Takeout A survey was conducted by Wakefield Research in which participants were asked to disclose their favorite night to order takeout for dinner. The following data are based on their results.

b. What is the probability a randomly selected individual would choose Friday as their favorite night to order takeout?

In the context of probability and statistics, primary data are —.

In probability theory, what is the probability of an event that is certain to occur?

Which of the following is a characteristic of nonprobability sampling?

If $134$ students in a class of $200$ passed an exam, what percent of the class passed?

In a study, the mean height of all students in a university is calculated using the heights of every student. Is this value a parameter or a statistic?

Nonresponse bias occurs when which of the following happens in a probability sample?

Consider the following probability distribution for a discrete random variable $X$: $X$: $1$ $2$ $3$ $4$, $P\left(X\right)$: $0.1$ $0.3$ $0.4$ $0.2$. Which of the following statements is true about this distribution?