STA 301 Midterm 1 Review

Front

Which of the following is an example of a discrete variable?
Weight of an apple,
Time it takes to finish a race,
Number of defective lightbulbs in a box,
Temperature outside tomorrow,
Height of a student

Back

Number of defective lightbulbs in a box

Front

Which of the following is an example of a numerical variable? Phone number, GPA, Zip code, Date of birth

Back

GPA

Front

In which of the following scenarios would a binomial distribution be appropriate?
Flipping a fair coin 10 times and counting the number of heads,
Drawing 10 cards from a standard deck without replacement and counting the number of hearts,
Observing the number of cars passing through an intersection in 1 hour,
Measuring the number of phone calls a call center receives in a day,
Recording the time it takes for a computer to finish 50 tasks

Back

Flipping a fair coin 10 times and counting the number of heads

Front

Which of the following statements regarding independence is true?
If P(A|B) = P(B|A), then the two events are independent.
If the probability of two events occurring are equal (P(A) = P(B)), they are independent.
If two events are independent, the probability of one event occurring affects the probability of the other event occurring.
If P(A|B) = P(B|not A), then the two events are independent.
None of the above

Back

None of the above

Front

In Suits, Louis Litt is reviewing 30 contracts, each with a 5% chance of a drafting error. What is the correct R code to calculate the probability Louis finds at least 2 errors?

Back

1 - pbinom(1, size = 30, prob = 0.05)

Front

Which of the following is true of the relationship between Jim and Dwight making sales?
The probability that Jim makes a sale on a given day is 0.6
The probability that Dwight makes a sale on a given day is 0.7
The probability that both Jim and Dwight make a sale on the same day is 0.5

Back

All of the above

Front

In a dataset, what does the unit of analysis refer to?

Back

The type of entity you choose to focus on

Front

In a survey of students, 55% drink coffee, 40% drink tea, and it is known that P(coffee|tea) = 0.50. What is the probability that a student drinks coffee or tea?

Back

0.75

Front

In a voter registration database, each registered voter has a unique 6-digit voter ID number. What kind of statistical variable is the voter ID?

Back

categorical

Front

A meteorologist wants to display the distribution of daily rainfall amounts in inches for a city over the past year. Which plot type would be most effective?

Back

Histogram