Statistics: Chapter 5 Test - Adolphson

Identify the given random variable as being discrete or continuous.

The number of students earning an A is Statistics this fall.

• discrete

• continuous

Identify the given random variable as being discrete or continuous.

The height (in inches) of each student in Statistics this fall.

• discrete

• continuous

Determine if the following is a probability distribution. If not, identify the requirement that is not satisfied.

A administration reports the probabilities that 0,1,2, and 3 fights occur in a single week at a school are 0.766, 0.204, 0.030, 0.0002, respectively.

• Yes

• No; the sum of probabilities is not 1

• No; all probabilities must be positive

Focus groups of 12 people are randomly selected to discuss Tik Tok. It is determined that the mean number (per group) who recognize the Tik Tok platform is 10.2, and the standard deviation is 1.1. Would it be unusual to randomly select 12 people and find that all 12 recognize the Tik Tok platform?

***Extra Credit if you post a home made Tik Tok that is Statistics related by the due date of this test. This can be done with a partner.

• Yes, some older people don't know what Tik-Tok is

• No; the upper limit for usual values in this case would 12.4

• Yes; the upper limit for usual values in this case would be 11.3

• No; Tik Tok is legit!

Assume that a researcher randomly selects 14 newborn babies and counts the number of girls selected.

Find the probability of selecting exactly 10 girls.

• 6.1%

• 61%

• 50%

• 10%

Assume that a researcher randomly selects 8 newborn babies and counts the number of girls selected.

Find the probability of selecting girls 2 or more girls.

• 3.1%

• 96.5%

• 3.5%

• 88%

Determine whether the given procedure results in a binomial distribution. If not, state why.

Choosing 5 people (without replacement) from a group of 400 people, of which 150 are women, keeping track of the number of men chosen.

• No; trials are not independent

• No; need to keep track of number of women instead

• Yes; 5 is less than 5% of sample so dependent trials can be treated as independent.

Determine whether the given procedure results in a binomial distribution. If not, state why.

Choosing 5 marbles from a box of 40 marbles (20 purple, 12 red, and 8 green) one at a time with replacement, keeping track of the number of green marbles chosen.

• Yes; fulfills all requirements.

• No; 5 is more than 5% of the population of marbles.

• No; must not use replacement.

Caribou Coffee has a 73% recognition rate. If a random sample of 10 people are selected, find the probability that the number of people who recognize the brand is NOT 8.

• 26.5%

• 73.5%

• 92%

• 8%

Caribou Coffee has a 73% recognition rate. If a random sample of 10 people are selected, would it be unusual for only 5 to recognize the brand?

• No; 5 is very close to 73%

• Yes; 5 is only half the people

• Yes; 5 is below 5.9, which is the lowest usual value when using the Range Rule of Thumb.

• No; 5 is above 4.5, which is the lowest usual value when using the Range Rule of Thumb