Question

In: Statistics and Probability

Forty-three percent of US teens have heard of a fax machine. You randomly select 12 US...

Forty-three percent of US teens have heard of a fax machine. You randomly select 12 US teens. Find the probability that the number of these selected teens that have heard of a fax machine is exactly six (first answer listed below). Find the probability that the number is more than 8 (second answer listed below).

Expert Solution

The random variable X denotes number of students that have heard of a fax machine.

p = probability of a students have heard of a fax machine. = 0.43

n = number of students randomly selected = 12

X takes value 0, 1, ..,12.

The probability distribution of a random variable X is binomial with n = 12 and p = 0.43

The probability mass function of X is

P( Exactly 6 students have heard of a fax machine ) = P (X =6)

P( Exactly 6 students have heard of a fax machine ) = 0.2003.

P ( More than 8 students have heard of a fax machine ) = P (X >8)

= P( X=9) + P(X =10) + P(X=11) + P(X=12).

P ( More than 8 students have heard of a fax machine )

= 0.0205 + 0.0046 + 0.0006 + 0.00003

= 0.02573

P ( More than 8 students have heard of a fax machine ) = 0.02573.

orchestra answered 2 years ago

Forty percent of a firm’s employees are men. Suppose Four of the firm’s employees are randomly...

Forty percent of a firm’s employees are men. Suppose Four of the firm’s employees are randomly selected. a. What is more likely, finding three men and one woman or two men and two women? _The probabilities of finding three men and one woman and two men and two women are the same. _Finding two men and two women are more likely. _Finding three men and one woman is more likely. b. Do you obtain the same answer as in part...

A survey of 1060 randomly selected US teens ages 13 to 17 found that 605 of...

A survey of 1060 randomly selected US teens ages 13 to 17 found that 605 of them say they have made a new friend online. Find and interpret a 90% confidence interval for the proportion of US teens who have made a new friend online. Fill in the blanks a) The scenario above represents (write either test or CI): b) The population parameter (write either single proportion or single mean): c) The sample size: d) The sample statistic (round decimal...

I have a statistics class of 20 students, of whom 12 are female. I randomly select...

I have a statistics class of 20 students, of whom 12 are female. I randomly select three students to make a group presentation to the class. What is the probability of the following occurring? a. All of the students in the group are male. b. One of the students in the group is male. c. Two of the students in the group are male. d. All three of the students in the group are female. e. Calculate the mean and...

Select a discussion about a difficult topic you have heard about. Begin with a statement. Write...

Select a discussion about a difficult topic you have heard about. Begin with a statement. Write out a comment for each of the 8 elements from the circle of elements: Purpose, Question, assumptions, Implications, information, concepts, conclusions and point of view.Select a discussion about a difficult topic you have heard about. Begin with a statement. Write out a comment for each of the 8 elements from the circle of elements: Purpose, Question, assumptions, Implications, information, concepts, conclusions and point of...

How about risks related to platform or environment? Have you heard "it worked on my machine"?...

How about risks related to platform or environment? Have you heard "it worked on my machine"? while it does not work on another machine. As we move on to the development, we will face similar issue in teams, please share experience how did you team solve this problem.

43% of adults say cashews are their favorite kind of nut. You randomly select 12 adults...

43% of adults say cashews are their favorite kind of nut. You randomly select 12 adults and ask each to name his or her favorite nut. Find the probability that the number who say cashews are their favorite nut is (a) exactly three, (b) at least four, and (c) at most two. If convenient, use technology to find the probabilities. P(3)=

According to the Consumer Electronics Manufacturers Association, 10% of all U.S households have a fax machine...

According to the Consumer Electronics Manufacturers Association, 10% of all U.S households have a fax machine and 52% have a personal computer. Suppose 91% of all U.S households having a fax machine also have a personal computer. a. What is the probability that a randomly selected US household has a fax machine and a personal computer? b. What is the probability that a randomly selected US household has a fax machine or personal computer? c. What is the probability that...

For two mutually exclusive machines, which machine will you select if the MARR is 12% based...

For two mutually exclusive machines, which machine will you select if the MARR is 12% based on the concept of IRR? Years CF for Machine A CF for Machine B 0 $ (120,000) $ (148,000) 1 $ 32,000 $ 46,000 2 $ 35,000 $ 49,000 3 $ 38,000 $ 52,000 4 $ 41,000 $ 52,000 5 $ 44,000 $ (52,000) 6 $ (24,000) $ 55,000 7 $ 47,000 $ 55,000 8 $ (21,000) $ (21,000) Machine A Machine B Both need to be rejected. Both are equally good.

Forty percent of students at a small college have brought their own personal computer to campus....

Forty percent of students at a small college have brought their own personal computer to campus. A random sample of 120 entering freshmen was taken. a. What is the standard error of the sample proportion bringing their own computer to campus. b. What is the probability that the sample proportions is less than 0.33? c. What is the probability that the sample proportion is between 0.38 and 0.46?

The probability that a person is left-handed is 17%. You randomly select three people. What is...

The probability that a person is left-handed is 17%. You randomly select three people. What is the probability that: a) all three are left handed b) none of them are left handed c) at least one of them is left-handed