14. An alcohol awareness task force at a Big-Ten university sampled 200 students after the midterm...

14. An alcohol awareness task force at a Big-Ten university sampled 200 students after the midterm to ask them whether they went bar hopping the weekend before the midterm or spent the weekend studying, and whether they did well or poorly on the midterm. The following result was obtained. (Please show the calculation process)

	Did Well on Midterm	Did Poorly on Midterm
Studying for Exam	80	20
Went Bar Hopping	30	70

Referring to above table, what is the probability that a randomly selected student did well on the midterm and went bar hopping the weekend before the midterm?

15. What is the probability that a randomly selected student did well on the midterm or went bar hopping the weekend before the midterm?

16. Referring to above table, the events "Did Well on Midterm" and "Studying for Exam" are

statistically dependent.
statistically independent.

Solutions

Expert Solution

	Did Well on Midterm	Did Poorly on Midterm	Total
Studying for Exam	80	20	100
Went Bar Hopping	30	70	100
Total	110	90	200

14. Probability that a randomly selected student did well on the midterm and went bar hopping the weekend before the midterm?

Answer : The number of students who did well and went bar hopping is 30.

p = 30/200

15. What is the probability that a randomly selected student did well on the midterm or went bar hopping the weekend before the midterm?

Answer : The number of students who did well or went bar hopping is 80+30+70 = 180.

p = 180/200

16. Referring to above table, the events "Did Well on Midterm" and "Studying for Exam" are

Events A and B are independent if the equation P(A∩B) = P(A) P(B) holds true.
statistically independent.

Events A and B are independent if the equation P(A∩B) = P(A) P(B) holds true.

P("Did Well on Midterm" and "Studying for Exam") =P("Did Well on Midterm") * P( "Studying for Exam")

80/200 =110/200 * 100/200

0.4 not equal to 0.275

Events "Did Well on Midterm" and "Studying for Exam" are statistically dependent.

Hope this will be helpful. Thanks and God Bless You :)

orchestra answered 1 year ago

Next > < Previous

Related Solutions

A task force is studying the need for an additional bicycle path on a large university...

A task force is studying the need for an additional bicycle path on a large university campus. It is assumed that the distribution of bicyclists using a path between classes is normally distributed with a population variance of about 64. A random sample of 7 existing bicycle paths showed that the sample mean number of bicyclists using a path between classes was 33. Construct a 95% confidence interval for the population mean number of bicyclists using a bicycle path.

A task force is studying the need for an additional bicycle path on a large university...

A task force is studying the need for an additional bicycle path on a large university campus. It is assumed that the distribution of bicyclists using a path between classes is normally distributed with a population variance of about 64. A random sample of 7 existing bicycle paths showed that the sample mean number of bicyclists using a path between classes was 33. A group of interested students took its own sample of 5 different bicycle paths, and computed a...

Are teacher evaluations independent of grades? After the midterm, a random sample of 284 students were...

Are teacher evaluations independent of grades? After the midterm, a random sample of 284 students were asked to evaluate teacher performance. The students were also asked to supply their midterm grade in the course being evaluated. In this study, only students with a passing grade were included in the summary table. Use a 5% level of significance to test the claim that teacher evaluations are independent of midterm grades. Midterm Grade Teacher Evaluation A B C Row total Positive 35...

Ten sampled students of 18-21 years of age received special training. They are given an IQ...

Ten sampled students of 18-21 years of age received special training. They are given an IQ test that is N (100, 102) in the general population. Let μ be the mean IQ of these students who received special training. The observed IQ scores: 121, 98, 95, 94,102, 106, 112, 120, 108, 109. Test if the special training improves the IQ score using significance level α = 0.05. a.What is the rejection region? b.Calculate the p-value and state your conclusion. c.What...

1) Out of 200 people sampled, 14 had kids. Based on this, construct a 95% confidence...

1) Out of 200 people sampled, 14 had kids. Based on this, construct a 95% confidence interval for the true population proportion of people with kids. Give your answers as decimals, to three places < p < 2) If n=450n=450 and ˆpp^ (p-hat) =0.91, find the margin of error at a 90% confidence level. Round to 4 places. z-scores may be rounded to 3 places or exact using technology. 3) In a recent poll, 110 people were asked if they...

The campus club, 'Don't Do Drugs!', is launching a public awareness campaign alerting university students to...

The campus club, 'Don't Do Drugs!', is launching a public awareness campaign alerting university students to the danger of using illegal drugs. William, the club chairman, recently bought a book at Borders called Drugs the Destroyer (price paid $25). John McBride is the author of the book. William wants to distribute 1,000 copies of the book as part of the public awareness campaign but the club doesn't have enough money to buy them.Instead, William scans the book onto his computer...

A local university wants to conduct a sample of 200 students out of 6000 students. We...

A local university wants to conduct a sample of 200 students out of 6000 students. We can assume that the university maintains a good roster of all registered students. (1) how would you select the 200 students(a) using simple random sample method and (b) systematic sampling method? (2) suppose that the university administration wants to make sure in particular students who major in music (a small department with only 8% of students major in music)be adequately included in your sample,...

8. At a university with 1,000 business majors, there are 200 business students enrolled in an...

8. At a university with 1,000 business majors, there are 200 business students enrolled in an introductory Accounting course. Of these 200 students, 50 are also enrolled in an introductory Statistics course. There are an additional 250 business students enrolled in Statistics but not enrolled in Accounting. If a business student is selected at random, what is the probability that the student is either enrolled in Accounting or Statistics or in both courses?

2. A survey of 200 students is selected randomly on a large university campus. They are...

2. A survey of 200 students is selected randomly on a large university campus. They are asked if they use a laptop in class to take notes. The result of the survey is that 128 of the 200 students responded ”yes." A. Find 98% confidence interval B. How would the confidence interval change if the confidence level had been 90% instead of 98%? C. How would the confidence interval change if the sample size had been 300 instead of 200?...

A survey of 200 students is selected randomly on a large university campus They are asked...

A survey of 200 students is selected randomly on a large university campus They are asked if they use a laptop in class to take notes. The result of the survey is that 70 of the 200 students use laptops to take notes in class. What is the value of the sample proportion? (0.5 pts) What is the standard error of the sampling proportion? (0.5 pts) Construct an approximate 95% confidence interval for the true proportion by going 2 standard...

Subjects