7. A study reported that 49 % of eighth-graders in the U.S. believe that smoking one pack of cigarettes a day does notpose a serious risk to their health. A researcher wanted to check whet her this result still holds true for the currentpopulation of eighth graders in the U.S. A random sample survey of 400 eighth-graders from the U.S. recently showedthat 176 of them believe that smoking one pack of cigarettes a day does not pose a serious risk to their health.Using 5 % significance level Test if the current proportion of all U.S. eight h-graders who hold this opinion is significantlyless than the 49%. ( State a null hypothesis H, and an alternative hypothesis Hạ, then perform the test ).8. The continuous random variable X measures the concentration of ethanol in a chemical solution and the continuousrandom variable Y measures the acidity of the solution. Suppose the variables have the following joint probabilitydensity function (pdf):f (r, y) = {-{s20 – z – 2y) if 0Sa5 5, 0Sy 55elsewhere(a) Find the marginal probability density function f, (y).(b) Find the probability P(Y >1+x).(c) Find the expectation of the product of ethanol concentration and acidity, denoted E (XY).

Since you have asked multiple question, we will solve the first question for you. If you want any…

Answered: 7. A study reported that 49 % of…

A First Course in Probability (10th Edition)

10th Edition

ISBN:9780134753119

Author:Sheldon Ross

Publisher:Sheldon Ross

Chapter1: Combinatorial Analysis

Section: Chapter Questions

Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...

See similar textbooks

Similar questions

8. Has the percentage of registered nurses earning more advanced academic degrees changed? In 1980 55% of registered nurses had a high school diploma as their highest level of education, 18% had an associate's degree, 22% had a bachelor's degree, and 5% had a master's degree. In 2012, a random sample of 800 registered nurses was obtained. Of those sampled, 111 had a high school diploma as their highest educational degree, 295 had an associate's degree, 289 had a bachelor's degree, and 105 had a master's degree. At the 5% significance level, what conclusion can be reached? slom Sor pot combcee
An article published in the “American Journal of Public Health” describes the results of a health survey administered to 119 male convicts, 50 years of age or older, residing in a state social rehabilitation center. It was found that 21.6% of them claimed to have a history of venereal diseases. Based on these findings, we wish to evaluate whether more than 15% of this population has a history of venereal diseases. After evaluating the information, what would be the conclusion? A. In the population of male convicts aged 50 years or older, residing in the state social rehabilitation center, more than 15% have a history of venereal diseases. B. In the population of male convicts aged 50 years or older, residing in the state social rehabilitation center, it is not possible to say that more than 15% have a history of venereal diseases. C. In the population of male convicts aged 50 years or older, residing in the state social rehabilitation center, on average more or less 21.6% have a…
According to the Pew Research Center, the proportion of the American population who use only a cellular telephone (no landline) is 0.37. Jason conducts a survey of thirty 20- to 24-year-olds who live on their own and finds that 16 do not have a landline to their home. Does this provide sufficient evidence to conclude that the proportion of 20- to 24-year-olds who live on their own and don’t have a landline is greater than 0.37? Use an a=0.10 level of significance. Note
1. In 1955, Life Magazine reported that a 25-year-old mother of 3 children, worked an average of 80 hours each week. Recently, some researchers have been studying whether the women’s movement has resulted in an increase in the work week hours for women (combining employment and at-home work). A study was done to find out if the mean work week has, in fact, increased. A random sample of 81 women were surveyed and the mean was 83 hours with a standard deviation of 10. Using a 95% confidence level, does the sample data support the researcher’s claim that the average number of weekly hours that women work, is greater than 80? a. What statistical test will you use to test this data ? b. State the null and alternative hypothesis. i. H0: ii. Ha: c. What are the confidence intervals? d. What is the value of the test statistic? e. What is the p-value? f. Circle/highlight the correct decision about the null hypothesis. Reject H0…
Labor Day was created by the U.S. labor movement over 100 years ago. It was subsequently adopted by most states as an official holiday. In a poll by Gallup, 1000 randomly selected adults were asked whether they approve of labor unions; 650 said yes. In 1936, about 72% of Americans approved of labor unions. At a 5% level of significance, do the data provide sufficient evidence to conclude that the percentage of Americans who approve of labor unions now has decreased since 1936? Solve using the critical-value approach. Define the parameter we are testing and setup a hypothesis test to see if less than 72% of Americans approve of labor unions currently. Calculate the test statistics for this hypothesis test. What is the critical value for this hypothesis test?
In a major urban area, the percentage of male drivers between the ages of 19 and 29 who did not regularly use seatbelts was 28%. After a major radio and television campaign and stricter enforcement by the local police, researchers want to know if the percentage of male drivers between the ages of 19 and 29 who did not regularly use seatbelts has decreased. They poll a random sample of 100 males between the ages of 19 and 29 and find the percentage who didn’t wear their seatbelt was 24%. (a) Identify the population, parameter, sample and statistic.(b) State appropriate hypotheses for performing a significance test.
Anterior cruciate ligament (ACL) injuries occur most frequently in planting and cutting sports such as basketball, soccer, and volleyball. A sports medicine researcher wants to test if female athletes are more likely to have an ACL injury than males. He surveyed 50 collegiate programs that had both men’s and woman’s volleyball and asked them how many grade 3 ACL tears they had during the past season. Which statistical test would be best to determine if there is a significant difference between groups?
The state highway department is studying traffic patterns on one of the busiest highways in the state. As part of the study, the department needs to estimate the average number of vehicles that pass an intersection each day. One of the department’s officer (Officer A) claims that on average, more than 15,000 cars passing the intersection. On the other hand, Officer B claims that on average, 18,000 cars passing the intersection. Meanwhile, a random sample of 64 days gives a sample mean of 14,205 cars and a sample standard deviation of 1,010 cars. Test both claim at 0.05 level of significance. Use the critical value approach and show the complete calculation steps for each testing. Whose claim is true? a)Testing Officer A’s claim State the hypotheses, find critical value and state the decision rule, compute the test value, make decision, conclusion. b) Testing Officer B’s claim State the hypotheses, find critical value and state the decision rule, compute the test value, make decision,…
In 1990, 58% of Americans 18 years old and older reported they have a great deal of concern regarding air pollution. A recent poll found that 592 of 1004 Americans 18 years old or older stated that they have a great deal of concern regarding the level of air pollution in American. Is there evidence to conclude that the current proportion of Americans having a great deal of concern about the level of air pollution in America is different from the 1990 proportion, with a 10% level of significance? State the null hypothesis, alternative hypothesis, test statistic, p-value and conclusion.
A magazine reports that women trust recommendations from a particular social networking site more than recommendations from any other social network platform. But does trust in this social networking site differ by gender? The following sample data show the number of women and men who stated in a recent sample that they trust recommendations made on this particular social networking site. Women Men Sample 150 170 Trust RecommendationsMade on the social networking site 117 102 (a) What is the point estimate of the proportion of women who trust recommendations made on this particular social networking site? (b) What is the point estimate of the proportion of men who trust recommendations made on this particular social networking site? (c) Provide a 95% confidence interval estimate of the difference between the proportion of women and men who trust recommendations made on this particular social networking site. (Round your answers to four decimal places.) to
It is believed that 11% of all Americans are left-handed. A college needs to know how many left-handed desks to place in the big lecture halls being constructed on its campus. In a random sample of 340 students from that college, whether or not a student was left-handed was recorded for each student. The college wants to know if the data provide enough evidence to show that students at this college have a different percentage of left- handers than the general American population? State the random variable, population parameter, and hypotheses. State the Type I and Type II errors in the context of this problem. a) The symbol for the random variable involved in this problem is ? ✓ The wording for the random variable in context is as follows: Select an answer b) The symbol for the parameter involved in this problem is The wording for the parameter in context is as follows: Select an answer c) Fill in the correct null and alternative hypotheses: Ho?? ✓ HA: ? ✓ ? ✓ d) A Type I error in the…
One personality test available on the World Wide Web has a subsection designed to assess the "honesty" of the test-taker. After taking the test and seeing your score for this subsection, you're interested in the mean score, μ , among the general population on this subsection. The website reports that μ is 148 , but you believe that μ is greater than 148 . You decide to do a statistical test. You choose a random sample of people and have them take the personality test. You find that their mean score on the subsection is 152 and that the standard deviation of their scores is 28 . Based on this information, answer the questions below. What are the null hypothesis ( H0 ) and the alternative hypothesis ( H1 ) that should be used for the test? H0 : μ is H1 : μ is In the context of this test, what is a Type I error?A Type I error is the hypothesis that μ is when, in fact, μ is .Suppose that you decide not to…

SEE MORE QUESTIONS

Recommended textbooks for you

A First Course in Probability (10th Edition)

Probability

ISBN:

9780134753119

Author:

Sheldon Ross

Publisher:

PEARSON

A First Course in Probability

Probability

ISBN:

9780321794772

Author:

Sheldon Ross

Publisher:

PEARSON

A First Course in Probability (10th Edition)

Probability

ISBN:

9780134753119

Author:

Sheldon Ross

Publisher:

PEARSON

A First Course in Probability

Probability

ISBN:

9780321794772

Author:

Sheldon Ross

Publisher:

PEARSON

SEE MORE TEXTBOOKS