Geo and Binomial practice

The American Red Cross says that about 11% of the U.S. population has Type B blood. A blood drive is being held at your school. How many blood donors should the American Red Cross expect to collect from until it gets a donor with Type B blood? 

• 9.1 donors
• 8.5 donors
• 10.3 donors
• Cannot be determined.

Tags

CCSS.HSS.MD.A.2

CCSS.HSS.MD.A.3

The American Red Cross says that about 11% of the U.S. population has Type B blood. A blood drive is being held at your school. What is the probability that the tenth blood donor is the first donor with Type B blood?

• approximately 0.00
• 0.316
• 0.0385 
• 0.279

The American Red Cross says that about 11% of the U.S. population has Type B blood. A blood drive is being held at your school.What is the probability that exactly 2 of the 20 blood donors have Type B blood?

• 0.316

• 0.282

• 0.001

• Not here

The American Red Cross says that about 11% of the U.S. population has Type B blood. A blood drive is being held at your school. What is the probability that at least 2 of the 10 blood donors has Type B blood?

• 0.088

• 0.697

• 0.214

• 0.303

A September 2011 Gallup survey suggests that 38% of Americans are planning on voting for Barack Obama in the 2012 presidential election. Among a random sample of 100 people, approximately how many would you expect to vote for Obama? 

• 38 people
• 42 people
• 6 people
• Cannot be determined

Tags

CCSS.HSS.MD.A.2

CCSS.HSS.IC.B.4

CCSS.HSS.IC.A.1

CCSS.HSS.MD.B.5

A test consists of 10 multiple choice questions with five choices for each question. As an experiment, you GUESS on each and every answer without even reading the questions.

What is the probability of getting exactly 6 questions correct on this test?

• 0.5505%

• 0.00001%

• 0.0064%

• 0.0002%

Which one of these variables is a continuous random variable?

• The time it takes a randomly selected student to complete an exam.
• The number of tattoos a randomly selected person has.
• The number of women taller than 68 inches in a random sample of 5 women. 
• The number of correct guesses on a multiple choice test. 

The owner of a pet store is trying to decide whether to discontinue selling specialty clothes for pets. She suspects that only 4% of the customers buy those clothes. The owner had 275 customers that day. Assuming this was a typical day, what is the mean and standard deviation of customers who buy specialty clothes? 

• 11 customers, give or take 3.25
• 25 customers, give or take 24.5
• 11 customers, give or take 3.32
• Not enough information.

Tags

CCSS.HSS.MD.A.2

CCSS.HSS.IC.B.4

CCSS.HSS.MD.A.3

CCSS.HSS.ID.A.4

If you were to flip a coin 20 times, what is the probability you would get at least 13 heads?

• .9423
• .1316
• .0577
• .0739

Tags

CCSS.HSS.CP.B.9

If you were to flip a coin 20 times, what is the probability you would get at most 13 heads?

• .9423
• .1316
• .0577
• .0739

Tags

CCSS.HSS.CP.B.9