12. A pollster wants to conduct a pre-election poll with a margin of error of 3.5% and a 95% confidencelevel. The pollster does not know ahead of time what the proportion in favor of either candidate is. Howmany people must be included in the sample to achieve the goal of a 3.5% margin of error? [Note that p-hat is unknown and is therefore assumed to be 0.5.]

Answered: 12. A pollster wants to conduct a…

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

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5.A random sample of 362 married couples found that 286 had two or more personality preferences in common. In another random sample of 550 married couples, it was found that only 30 had no preferences in common. Let p1 be the population proportion of all married couples who have two or more personality preferences in common. Let p2 be the population proportion of all married couples who have no personality preferences in common. Find a 90% confidence interval for p1 – p2. (Use 3 decimal places.) lower limit upper limit
Here is an explanation from the Associated Press concerning one of its opinion polls. Explain briefly but clearly in what way this explanation is incorrect. For a poll of 1,600 adults, the variation due to sampling error is no more than three percentage points either way. The error margin is said to be valid at the 95 percent confidence level. This means that, if the same questions were repeated in 20 polls, the results of at least 19 surveys would be within three percentage points of the results of this survey.
1a) Manual Transmission Automobiles In 1980 more than 35% of cars purchased had a manual transmission (i.e. stick shift). By 2007 the proportion had decreased to 7.7%. A random sample of college students who owned cars revealed the following: out of 130 cars, 24 had stick shifts. Estimate the proportion of college students who drive sticks with 90% confidence. Use a graphing calculator and round the answers to at least three decimal places. b) Belief in Haunted Places A random sample of 305 college students were asked if they believed that places could be haunted, and 44 responded yes. Estimate the true proportion of college students who believe in the possibility of haunted places with97% confidence. According to Time magazine, 37% of Americans believe that places can be haunted. Round the answers to at least five decimal places. Use a graphing calculator. ___ < p < ___ c) Travel to Outer Space A CBS News/New York Times poll found that 329 out of 763 randomly selected…
Fear of the dark is quite common among children. However, what about adults? One polling agency released the results of a survey that asked people over 30 years old if they keep the lights on at night. Among 452 respondents, 34% indeed leave the light on when going to sleep. What does this margin of error tell you about the percentage of adults who keep the lights on at night? We can be 95% confident that somewhere between % and % of adults keep the lights on at night.
A political researcher takes a survey of 310 randomly selected registered voters in Orlando, and each person was asked who they plan on voting for in the 2024 presidential election. 110 said they plan on voting for Candidate A, 185 said they plan on voting for Candidate B, and 15 were unsure or plan to vote for another candidate. The researcher wants to construct a 95% confidence interval for the proportion of all registered voters in Orlando who plan to vote for Candidate B. What is the point estimate? Round final answer to 3 decimal places.
4.A prior study(by Pew Research 2021)found that 35 out of 50 randomly selected US adults between the ages of 18 to 29 use (or have used) Instagram. Construct a 99% confidence interval for the population proportion of US adults between the ages of 18 to 29 use (or have used) Instagram. (round to three decimal places) a.Identify the following: X, N, P b.Which distribution should you use for this problem? c.What is the corresponding critical value for a 99% confidence interval? d.Calculate the margin of error (3 decimal places) e.Construct a 99% confidence interval f. Interpret the interval.
6. A researcher takes a sample of people, and asks them how they would vote for president. When she creates her confidence interval, she has a standard error of .082. If she wanted to get a smaller standard error, what could she do? Group of answer choices Ask a different research question. Take a smaller sample. Take a larger sample. None of the above would create a smaller standard error.
46. A polling company is trying to estimate the percentage of adults that consider themselves happy. A confidence interval based on a sample size of 360 has a larger than the desired margin of error. The company wants to conduct another poll and obtain another confidence interval of the same level but reduce the error to one-third of the size of the original sample. How many adults should they now interview? 1080 3240 40 120 O O
1.A poll questioned 800 students about their views on pizza for lunch at school. The results indicated that 65% of respondents felt that pizza was a must for lunch at school and would quit school if there was no pizza at lunch. a) Determine the 90% confidence interval. b) What is the margin of error for this response at the 90% confidence level?
The Department of Health and Human Services has been asked to estimate the proportion of "latch-key" children (children who have their own key and come home to an empty house) in New Jersey. This estimate is to be within plus or minus 0.03 of the true population proportion with a 98% level of confidence. The head of the Department's Family Division has no idea of what this proportion might be, so she uses 0.5 as the “estimate" of p. What size sample of New Jersey's children should be taken? 5.
In a recent poll of 1,003 people conducted by Ipsos Ipsos (see: https://projects.fivethirtyeight.com/biden-approval-rating/ ), 53% of the respondents disapproved of President Biden. Find a 95% confidence interval for the proportion of all people who disapprove of President Biden. Find a 99% confidence interval for the proportion of all people who disapprove of President Biden. What are the respective margins of errors in parts a) and b) and why are they different?
13. We have used a confidence level of 95% to estimate the average hours of television viewing for residents in a retirement home. What is the chance that our interval estimate does not contain the true population mean? (4%) A. 95% B. 5% C. 2.5% D. None of the above 14. There are about 4 million eligible voters in a society. A public opinion pollster has estimated their probable choices for the next president with a sample of 4,000 randomly selected citizens. In this example, the 4,000 citizens are a _____ and the 4 million eligible voters are a _____. (4%) A. Population, sample B. Statistics, parameters C. Parameters, statistics D. sample, population 15. In developing an interval estimate for a population mean, the population standard deviation was known. A 95% confidence interval was used. The interval estimate was [30 - 3:92; 30 + 3:92]. What would be the interval estimate if sample size (n) is quadrupled?…

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