Mean Standard Deviation Binomial Distribution

Find the mean of the binomial distribution for which n = 40 and p = 0.2.

• 20

• 40

• 2.53

• 8

Find the variance of the binomial distribution for which n =800 and p= 0.87

• 90.48

• 696

• 9.51

• 32.54

Find the standard deviation of the binomial distribution for which n=1000 and p= 0.94.

• 56.7

• 6.31

• 940

• 7.51

A test consists of 700 true or false questions. If the student guesses on each question, what is the mean number of correct answers?

• 350

• 0

• 140

• 700

A test consists of 800 true or false questions. If the student guesses on each question, what is the standard deviation of the number of correct answers?

• 14.14

• 32.42

• 400

• 199.94

In one city,24% of adults smoke. In groups of size 130 of adults, what is the variance of the number that smoke ?

• 31.2

• 11.86

• 23.71

• 4.87

A test consists of 100 multiple choice questions, each with five possible answers, only one of which is correct. Find the standard deviation of the number of correct answers.

• 4.47

• 4

• 7.07

• 16

An algebra 2 test has 6 multiple choice questions with four choices with one correct answer each. If we just randomly guess on each of the 6 questions, what is the probability that you get exactly 3 questions correct?

• 0.962

• 0.132

• 0.831

• 0.250

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 first 10 blood donors has Type B blood? 

• 0.088
• 0.697
• 0.214
• 0.303 

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 first 20 blood donors have Type B blood? 

• 0.316
• 0.282
• 0.001
• Not here