3. In a Harris poll of 2036 adults, 40% said that they prefer to get their...

3. In a Harris poll of 2036 adults, 40% said that they prefer to get their news online.

a. Construct a 95% confidence interval estimate of the percentage of all adults who say that they prefer to get their news online.

b. Can we safely say that fewer than 50% of adults prefer to get their news online?

Solutions

Expert Solution

Solution :

Given that,

n = 2036

Point estimate = sample proportion = = 0.40

1 - = 1- 0.40 =0.60

At 95% confidence level the z is ,

= 1 - 95% = 1 - 0.95 = 0.05

/ 2 = 0.05 / 2 = 0.025

Z/2 = Z0.025 = 1.96 ( Using z table )

Margin of error = E = Z/2 * $\sqrt$ ((( * (1 - )) / n)

= 1.96 ( $\sqrt$ ((0.4*0.6) /2036 )

E = 0.0213

A 95% confidence interval for population proportion p is ,

- E < p < + E

0.40- 0.0213< p <0.40+ 0.0213

0.3787< p < 0.4213

The 95% confidence interval for the population proportion p is : 0.3787, 0.4213

orchestra answered 1 year ago

Next > < Previous

Related Solutions

QUESTION #3. In another Harris poll, adults were asked if they are in favor of abolishing...

QUESTION #3. In another Harris poll, adults were asked if they are in favor of abolishing the penny. Among 200 responses, 104 answered “yes.” a) Use a 0.07 significance level to test the claim that the population proportion of the people who answered “yes” is the same as 50%. b) What does the conclusion mean? QUESTION #4. In a survey, 716 out of 1132 randomly selected adults in the United States said that they use cell phones while driving. a)...

Based on a Harris Interactive poll, 20% of adults believe in reincarnation. Assume that 6 adults...

Based on a Harris Interactive poll, 20% of adults believe in reincarnation. Assume that 6 adults are randomly selected. Determine each probability to 4 decimal places. A. Exactly 5 of the selected adults believe in reincarnation B. At least 5 of the randomly selected adults believe in reincarnation C. At most 5 of the randomly selected adults believe in reincarnation

In a Harris poll of 514 human resource professionals, 90% said that the appearance of a...

In a Harris poll of 514 human resource professionals, 90% said that the appearance of a job applicant is most important for a good first impression. Construct a 99% confidence interval for the proportion of all human resource professionals believing that the appearance of a job applicant is most important for a good first impression. Also, find the margin of error.

In a Harris poll of 514 human resource professionals, 45.9% said that body piercings and tattoos...

In a Harris poll of 514 human resource professionals, 45.9% said that body piercings and tattoos were big grooming red flags. A professor of personnel managements believes that fewer than half of all human resources professionals would say that body piercings and tattoos were big grooming red flags. Use a significance level of 0.01 and 0.05 H0: _____ _____ ______ Ha: _____ _____ ______ a. Follow our procedure on page 2 of our Unit 3 Day 1 notes to bracket...

Based on a poll, 40% of adults believe in reincarnation. Assume that 8 adults are randomly...

Based on a poll, 40% of adults believe in reincarnation. Assume that 8 adults are randomly selected, and find the indicated probability?

Harris Interactive® conducted a poll of American adults in August of 2011 to study the use...

Harris Interactive® conducted a poll of American adults in August of 2011 to study the use of online medical information. Of the 1,019 randomly chosen adults, 60% had used the Internet within the past month to obtain medical information. Use the results of this survey to create an approximate 95% confidence interval estimate for the percentage of all American adults who have used the Internet to obtain medical information in the past month. Calculate the 90% confidence interval. Which confidence...

A poll found that 74% of a random sample of 1029 adults said that they believe...

A poll found that 74% of a random sample of 1029 adults said that they believe in ghosts. determine the margin of error

A poll surveyed 341 video gamers, and 95 of them said they prefer playing games on...

A poll surveyed 341 video gamers, and 95 of them said they prefer playing games on a console, rather than a computer or hand-held device. An executive at a game console manufacturing company claims that the proportion of gamer who prefer consoles differs from 29%. Does the poll provide convincing evidence that the claim is true? Use the a= 0.05 level of significance and the P- method with the TI -84 Calculator.

A poll surveyed 341 video gamers, and 99 of them said that they prefer playing games...

A poll surveyed 341 video gamers, and 99 of them said that they prefer playing games on a console, rather than a computer or hand-held device. An executive at a game console manufacturing company claims that the proportion of gamers who prefer consoles differs from 28%. Does the poll provide convincing evidence that the claim is true? Use the =α0.01 level of significance and the P-value method.

In a poll 1040 of 2260 respondents said they would prefer to live somewhere else. Confirm...

In a poll 1040 of 2260 respondents said they would prefer to live somewhere else. Confirm the distribution for p-hat is approximately normal and find a 95% confidence interval for the proportion of people who prefer to live somewhere else.

Subjects