91影视

The two-way table summarizes data on whether students at a certain high school eat

regularly in the school cafeteria by grade level.

a. If you choose a student at random, what is the probability that the student eats

regularly in the cafeteria and is not a $10th鈥�$grader?

b. If you choose a student at random who eats regularly in the cafeteria, what is the probability that the student is a $10th鈥�$grader?

c. Are the events 鈥�$10th鈥�$grader鈥� and 鈥渆ats regularly in the cafeteria鈥� independent?

Justify your answer.

Three machines鈥擜, B, and C鈥攁re used to produce a large quantity of identical parts at

a factory. Machine A produces $60\%$of the parts, while Machines B and C produce

$30\%$and $10\%$of the parts, respectively. Historical records indicate that $10\%$of the parts

produced by Machine A are defective, compared with $30\%$for Machine B, and $40\%$for

Machine C. Suppose we randomly select a part produced at the factory.

a. Find the probability that the part is defective.

b. If the part is inspected and found to be defective, what鈥檚 the probability that it was

produced by Machine B?

At Dicey Dave鈥檚 Diner, the dinner buffet usually costs $12.99. Once a month, Dave sponsors 鈥渓ucky buffet鈥� night. On that night, each patron can either pay the usual price or roll two fair, six-sided dice and pay a number of dollars equal to the product of the numbers showing on the two faces. The table shows the sample space of this chance process.

a. A customer decides to play Dave鈥檚 鈥渓ucky buffet鈥� game. Find the probability that the customer will pay less than the usual cost of the buffet.

b. A group of 4 friends comes to Dicey Dave鈥檚 Diner to play the 鈥渓ucky buffet鈥� game. Find the probability that all 4 of these friends end up paying less than the usual cost of the buffet.

c. Find the probability that at least 1 of the 4 friends ends up paying more than the usual cost of the buffet

Based on previous records, 17% of the vehicles passing through a tollbooth have out-ofstate plates. A bored tollbooth worker decides to pass the time by counting how many vehicles pass through until he sees two with out-of-state plates. We would like to perform a simulation to estimate the average number of vehicles it takes to find two with out-of-state plates.30

a. Describe how you would use a table of random digits to perform the simulation.

b. Perform 3 trials of the simulation using the random digits given here. Copy the digits onto your paper and mark directly on or above them so that someone can follow what you did.

What is the probability that the person owns a Chevy, given that the truck has four-wheel drive?

$$\begin{gathered} a.32/50 \\ b.32/80 \\ c.32/125 \\ d.50/125 \\ e.80/125 \end{gathered}$$

Which one of the following is true about the events 鈥淥wner has a Chevy鈥� and

鈥淥wner鈥檚 truck has four-wheel drive鈥�?

a. These two events are mutually exclusive and independent.

b. These two events are mutually exclusive, but not independent.

c. These two events are not mutually exclusive, but they are independent.

d. These two events are neither mutually exclusive nor independent.

e. These two events are mutually exclusive, but we do not have enough information to determine if they are independent.

A spinner has three equally sized regions: blue, red, and green. Jonny spins the spinner $3$times and gets $3$blues in a row. If he spins the spinner $297$more times, how many more blues is he most likely to get?

$$\begin{gathered} a.97 \\ b.99 \\ c.100 \\ d.101 \\ e.103 \end{gathered}$$

Which of the following is a correct way to perform the simulation?

a. Let integers from $1to34$represent making a free throw and $35to50$represent missing a free throw. Generate $50$random integers from$1to50$. Count the number

of made free throws. Repeat this process many times.

b. Let integers from $1to34$represent making a free throw and $35to50$represent missing a free throw. Generate 50 random integers from 1 to 50 with no repeats

allowed. Count the number of made free throws. Repeat this process many times.

c. Let integers from$1to56$represent making a free throw and $57to100$represent missing a free throw. Generate 50 random integers from$1to100.$Count the number of made free throws. Repeat this process many times.

d. Let integers from localid="1653986588937" $1to56$represent making a free throw and localid="1653986593808" $57to100$represent missing a free throw. Generate 50 random integers from localid="1653986598680" $1to100$with no repeats allowed. Count the number of made free throws. Repeat this process many times.

e. None of the above is correct.

The dotplot displays the number of made shots in $100$simulated sets of $50$free throw by someone with probability $0.56$of making a free throw.

Which of the following is an appropriate statement about Wilt鈥檚 free-throw shooting

based on this dotplot?

a. If Wilt were still only a $56\%$shooter, the probability that he would make at least $34$of his shots is about$0.03.$

b. If Wilt were still only a $56\%$shooter, the probability that he would make at least $34$of his shots is about $0.97.$.

c. If Wilt is now shooting better than $56\%$, the probability that he would make at least $34$of his shots is about $0.03.$

d. If Wilt is now shooting better than$56\%$, the probability that he would make at least $34$of his shots is about$0.97.$

e. If Wilt were still only a $56\%$shooter, the probability that he would make at least $34$of his shots is about $0.01$.

The partially complete table that follows shows the distribution of scores on the AP庐

Statistics exam for a class of students.

Select a student from this class at random. If the student earned a score of 3 or higher

on the AP庐 Statistics exam, what is the probability that the student scored a 5?