Statistics and Probability Review

W­­­­hich of the following is NOT a discrete variable?

• Number of books per student.

• Number of green marbles in the box.

• The weight of a case of soft drinks labeled 12 ounces.

• The number of arrivals of customers in the clinic between 8:00 a.m. to 4:00 p.m.

You decide to collect a bunch of bottles of soft drink and measure the volume of soft drink in each bottle. Let X be the number of ml of soft drink in each bottle. What type of variable is X?

• X is a constant

• X is a place holder

• X is a discrete random variable

• X is a continuous random variable.

In a local community, a couple was asked, “Are you satisfied with the work of the current president?” If the husband and the wife both said “yes”, the response is written as YY. If the husband said yes and the wife said “no”, the response is YN. If X is the number of “yes” responses, what are the possible values of the random variables?

• 0, 1, 2

• 1, 1, 2

• 1, 2, 3

• 2, 3, 4

Tags

CCSS.HSF-LE.A.1B

Suppose two laptops are tested. Let D represent the defective laptop and N represent the non-defective laptop. What is the possible sample space for the experiment?

• {DD, NN}

• {DD, DN, NN}

• {DD, ND, NN}

• {DD, DN, NN, ND}

Tags

CCSS.7.SP.C.8B

Consider the given probability distribution. What is the expected value (mean) of X, representing the average number of goals scored by the team?

• 1.7

• 2

• 1.3

• 1.5

Tags

CCSS.HSS.MD.A.2

Consider the given probability distribution table. If the random variable X represents the number of goals scored by a soccer team, what is the probability that the team scores no more than 2 goals?

• 0.6

• 0.8

• 0.7

• 0.9

Which of the following represents the expected value of the discrete random variable?

• mean

• mode

• median

• variance

Tags

CCSS.HSS.MD.A.2

The score of Grade 11 students in statistics and probability exam show that students excel in this subject. Assume that the distribution is normal with a mean grade of 20 and standard deviation of 2. If student is selected at random, find the probability of the students who got above 24 in their score.

• There is value of 2 in Grade 11 students who is above 24 in their score in statistics and probability exam.

• There are 20 Grade 11 students who got a raw score of 24 in their statistics and probability exam.

• There are 97.72% of Grade 11 students who got above 24 in their score in statistics and probability exam.

• There are 47.72% of Grade 11 students who got above 24 in their score in statistics and probability exam.

Tags

CCSS.HSS.ID.A.4

Researchers conduct a survey to senior high school students. Results shows the average data is 38.9 and a standard deviation of 3.4. If the respondent is selected randomly, find the probability that is below 40.

• Respondents who got below 40 is 50%

• Respondents who got below 40 is 12.55%

• Respondents who got below 40 is 37.45%

• Respondents who got below 40 is 62.55%

Tags

CCSS.HSS.ID.A.4

A test in Mathematics is normally distributed with mean of 80 and standard deviation of 5. Find the probability of the students who got above 75 grades.

• 100% of the students got a grade above 75

• 84.13% of the students got a grade above 75

• 34.13% of the students got a grade above 75

• 15.87% of the students got a grade above 75

Tags

CCSS.HSS.ID.A.4