Answered step by step
Verified Expert Solution
Link Copied!

Question

1 Approved Answer

Directions: Please respond to the questions listed below. For These you can give direct answers with no explanation. Note: THIS ISNT FOR AN ASSIGNMENT BUT

Directions: Please respond to the questions listed below.

For These you can give direct answers with no explanation.

Note: THIS ISNT FOR AN ASSIGNMENT BUT MERELY FOR MY OWN UNDERSTANDING AND COMPREHENSION! PLEASE BE ORGINAL! THIS IS FOR PRACTICE.

image text in transcribedimage text in transcribedimage text in transcribedimage text in transcribedimage text in transcribedimage text in transcribedimage text in transcribedimage text in transcribedimage text in transcribedimage text in transcribedimage text in transcribedimage text in transcribedimage text in transcribed
A TV newscaster reports the results of a poll of voters, and then says, "The margin of error is plus or minus 9%." Explain carefully what that means. Choose the correct answer below. O A. The proportion of the population who voted for one candidate is 9% less than the percent of the population who voted for the other candidate. B. The sample proportion is within 9% of her estimate, with some degree of confidence. O C. It means that 9% of the polls are invalid. O D. The true proportion is within 9% of her estimate, with some degree of confidence.A poll taken this year asked 1050 adults whether they were fans of a particular sport and 55% said they were. Last year, 54% of a similar-size sample had reported being fans of the sport. Complete parts a through e below. a) Find the margin of error for the poll taken this year if one wants 95% confidence in the estimate of the percentage of adults who are fans of the sport. ME = (Round to three decimal places as needed.) b) Explain what that margin of error means. O A. In 95% of samples of adults, the proportion who are fans of the sport will be within # ME of the sample proportion. O B. There is a 95% chance that the true proportion of adults who are fans of the sport is within + ME of this sample proportion. O C. One is 95% confident that this sample proportion is within + ME of the true proportion of adults who are fans of the sport. O D. One is 95% + ME confident that the true proportion of adults who are fans of the sport is equal to this sample proportion. c) If one wanted to be 99% confident instead of 95% confident, would the margin of error be larger or smaller? O A. To be more confident, the interval needs to contain the true proportion less often, so the margin of error would be larger. O B. To be more confident, the interval needs to contain the true proportion more often, so the margin of error would be larger. O C. To be more confident, the interval needs to contain the true proportion more often, so the margin of error would be smaller. O D. To be more confident, the interval needs to contain the true proportion less often, so the margin of error would be smaller. d) Find the margin of error for the poll taken this year if one wants 99% confidence in the estimate of the percent of adults who are fans of the sport. ME = (Round to three decimal places as needed.) e) In general, if all other aspects of the situation remain the same, will smaller margins of error produce greater or less confidence in the interval? O Greater confidence O Less confidenceA magazine is considering the launch of an online edition. The magazine plans to go ahead only if it is convinced that more than 15% of current readers would subscribe. The magazine contacted a simple random sample of 400 current subscribers, and 66 of those surveyed expressed interest. What should the company do? Test appropriate hypotheses and state your conclusion Are the assumptions and the conditions to perform a one-proportion z-test met? O Yes O No State the null and alternative hypotheses. Choose the correct answer below. O A. Ho: P = 0.15 HA: p #0.15 O B. Ho: P = 0.15 HA: p > 0.15 O C. Hip = 0.15 HA: p 0.39 (Type integers or decimals.) The test statistic is z= 0.54 . (Round in two decimal places as needed.) The Pwelue is . (Round to three decimal places as needed.) sate your conclusion. Use a = 0.05. V the null hypothesis. There V suicient evidence to conclude that the proportion of students in the high school who were harassed while online is V the proportion of people from the region being harassed while online. It's believed that as many as 19% of adults over 50 never graduated from high school. We wish to see if this percentage is the same among the 25 to 30 age group. a) How many of this younger age group must we survey in order to estimate the proportion of non-grads to within 6% with 90% confidence? n= 116 (Round up to the nearest integer.) b) Suppose we want to cut the margin of error to 4%. What is the necessary sample size? n= 261 (Round up to the nearest integer.) c) What sample size would produce a margin of error of 3%. n= 482 (Round up to the nearest integer.)An organization monitors many aspects of elementary and secondary education nationwide. Their 1998 numbers are often used as a baseline to assess changes. In 1998, 33% of students had not been absent from school even once during the previous school year. In the 2002 survey, responses from 8592 randomly selected students showed that this figure had slipped to 32%. Officials would, of course, be concerned if student attendance were declining. Do these figures give evidence of a change in student attendance? Complete parts a through e below. a) Write appropriate hypotheses. Ho HA: b) Check the assumptions and conditions. The independence assumption justified. The 10% condition satisfied. The success/failure condition satisfied. c) Perform the test and find the P-value. The test statistic is z =]. (Round to two decimal places as needed. ) The P-value is]. (Round to three decimal places as needed.) d) State your conclusion. Use ( = 0.1. the null hypothesis. There sufficient evidence to conclude that the proportion of students with perfect attendance e) Do you think this difference is meaningful? Explain. O A. The difference must be meaningful because it is statistically significant. O B. The difference is probably meaningful because the observed change in the sample is large enough to be important and the results indicate that it is statistically significant. O C. The difference is not meaningful because it is not statistically significant. O D. The difference is probably not meaningful. The observed change in the sample is quite small, so even though it is statistically significant, it does not indicate a large enough change to be meaningful.Of 565 samples of seafood purchased from various kinds of food stores in different regions of a country and genetically compared to standard gene fragments that can identify the species, 67% were mislabeled. a) Construct a 99% confidence interval for the proportion of all seafood sold in the country that is mislabeled or misidentified. b) Explain what your confidence interval says about seafood sold in the country. c) A government spokesperson claimed that the sample size was too small, relative to the billions of pieces of seafood sold each year, to generalize. Is this criticism valid? a) What is the 99% confidence interval? The 99% confidence interval is from % to% (Round to one decimal place as needed.) b) What does the confidence interval say about seafood sold in the country? O A. There is a 99% chance that the true proportion of mislabeled seafood is in the interval. O B. We are 99% confident that the interval captures the true proportion of all seafood sold in the country that is mislabeled. O C. In 99% of samples of seafood sold in the country, the proportion that is mislabeled will be in the interval. c) Is the government spokesperson's criticism valid? O A. No, as long as the necessary assumptions and conditions were met, the results can be generalized. O B. Yes, the sample size must be at least 10% of the population, or the results cannot be generalized. O C. No, until another study produces a different interval, the results should be generalized.Wildlife biologists inspect 156 deer taken by hunters and find 28 of them carrying ticks that test positive for Lyme disease. a) Create a 90% confidence interval for the percentage of deer that may carry such ticks. (Round to one decimal place as needed.) b) If the scientists want to cut the margin of error in half, how many deer must they inspect? c) What concerns do you have about this sample? O A. Since females and young deer are usually not hunted, this sample may not be representative of all deer. Also, since deer ticks are parasites and can easily be spread from one deer to another, the ticks may not be distributed evenly throughout the deer population. O B. Since deer ticks are parasites and can easily be spread from one deer to another, the ticks may not be distributed evenly throughout the deer population. O C. Since females and young deer are usually not hunted, this sample may not be representative of all deer. O D. There are no concerns about this study.An insurance company checks police records on 555 accidents selected at random and notes that teenagers were at the wheel in 92 of them. Complete parts a) through d). a) Construct the 95% confidence interval for the percentage of all auto accidents that involve teenage drivers. 95% CI = (*%.%) (Round to one decimal place as needed.) b) Explain what your interval means. O A. We are 95% confident that a randomly sampled accident would involve a teenager a percent of the time that falls inside the confidence interval limits. O B. We are 95% confident that the percent of accidents involving teenagers is 16.6%. O C. We are 95% confident that the true percentage of accidents involving teenagers falls inside the confidence interval limits. c) Explain what "95% confidence" means. About 95% of random samples of size 555 will produce that contain(s) the of accidents involving teenagers. d) A politician urging tighter restrictions on drivers' licenses issued to teens says, "In one of every five auto accidents, a teenager is behind the wheel." Does the confidence interval contradict this statement? O A. The confidence interval does not contradict the assertion of the politician. The figure quoted by the politician is outside the interval. O B. The confidence interval contradicts the assertion of the politician. The figure quoted by the politician is outside the interval. O C. The confidence interval does not contradict the assertion of the politician. The figure quoted by the politician is inside the interval. O D. The confidence interval contradicts the assertion of the politician. The figure quoted by the politician is inside the interval.A city ballot includes a local initiative that would legalize gambling. The issue is hotly contested, and two groups decide to conduct polls to predict the outcome. The local newspaper finds that 54% of 150 randomly selected voters plan to vote "yes," while a college Statistics class finds 53% of 1400 randomly selected voters in support. Both groups will create 90% confidence intervals. Assume that all voters know how they intend to vote and that the initiative requires a majority vote to pass. Complete parts a through c below. a) Without finding the confidence intervals, explain which one will have the larger margin of error. will have the larger margin of error, at least mainly because b) Find both confidence intervals. The confidence interval for the local newspaper is (1%, 7%). (Round to one decimal place as needed.) The confidence interval for the college Statistics class (Round to one decimal place as needed.) c) Which group concludes that the outcome is too close to call? Why? that the outcome is too close to call, since the interval(s) obtained by this/these group(s)According to a regional association of medical colleges, only 42% of medical school applicants were admitted to a medical school in the fall of 2011. Upon hearing this, the trustees of Striving College expressed concern that only 71 of the 180 students in their class of 2011 who applied to medical school were admitted. The college president assured the trustees that this was just the kind of year-to-year fluctuation in fortunes that is to be expected and that, in fact, the school's success rate was consistent with the regional average. Complete parts a through c. a) What are the hypotheses? Ho: P 0.42 HA: P 0.46 (Type integers or decimals.) b) Check the conditions and find the P-value. Which assumptions and conditions below are met? Select all that apply. A. The randomization condition is met. B. The success/failure condition is met. C. The independence assumption is met. D. The 10% condition is met. What is the test statistic z? z= (Round to two decimal places as needed.) What is the P-value? P-value = (Round to three decimal places as needed.) c) Are the trustees right to be concerned, or is the president correct? Explain. The because the P-value provides that the percentage of students in the class of 2011 who applied to medical school were admitted is the percentage of admission according to the regional association of medical colleges.Several factors are involved in the creation of a confidence interval. Among them are the sample size, the level of confidence, and the margin of error. Which statements are true? a) For a given sample size, higher confidence means a smaller margin of error. This statement is b) For a specified confidence level, larger samples provide smaller margins of error. This statement is c) For a fixed margin of error, larger samples provide greater confidence. This statement is d) For a given confidence level, halving the margin of error requires a sample size twice as large. This statement isWrite the null and alternative hypotheses you would use to test each of the situations in parts (a) through (c). (a) A dictator is concerned about his "positives," that is, the percentage of the country's residents who express approval of his job performance. His political committee pays for a series of TV ads, hoping that they can keep the positives above 38%. They will use follow up polling to assess the ads' effectiveness. Let p be the proportion of the country's residents who express approval of the dictator's performance. Ho: P 0.38 HA: P 0.38 (b) is a six section spinner fair? Let p represent the probability of the spinner landing on any particular section. Ho: P HA: P (c) Only about 30% of people who try to win more friends succeed. Sellers of a motivational tape claim that listening to the recorded messages can help people succeed. Let p be the proportion of people who try to win more friends and succeed. Ho: P 0.30 HA: P 7 0.30

Step by Step Solution

There are 3 Steps involved in it

Step: 1

blur-text-image

Get Instant Access to Expert-Tailored Solutions

See step-by-step solutions with expert insights and AI powered tools for academic success

Step: 2

blur-text-image

Step: 3

blur-text-image

Ace Your Homework with AI

Get the answers you need in no time with our AI-driven, step-by-step assistance

Get Started

Recommended Textbook for

Calculus Early Transcendentals Early Transcendentals

Authors: Dennis G Zill, Warren S Wright

4th Edition

0763797375, 9780763797379

More Books

Students also viewed these Mathematics questions

Question

What is the investment income account of the balance of payments?

Answered: 1 week ago

Question

The quality of the proposed ideas

Answered: 1 week ago

Question

The number of new ideas that emerge

Answered: 1 week ago