A poll conducted in 2013 surveyed a random sample of 2003 American adults, and 18% of...

A poll conducted in 2013 surveyed a random sample of 2003 American adults, and 18% of them said that they have seen a ghost. Construct a 95% confidence interval for the proportion of American adults who have seen a ghost.

Solutions

Expert Solution

Solution :

Given that,

n = 2003

Point estimate = sample proportion = =18%=0.18

1 - = 0.82

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 ( $\sqrt$ ((0.18*0.82) /2003 )

E = 0.017

A 95% confidence interval for population proportion p is ,

- E < p < + E

0.18 - 0.017 < p < 0.18+0.017

(0.163 , 0.197)

orchestra answered 1 year ago

Next > < Previous

Related Solutions

A Pew Poll conducted in 2017 surveyed a random sample of 200 adult Americans and 75...

A Pew Poll conducted in 2017 surveyed a random sample of 200 adult Americans and 75 of them said that they had seen a ghost. Find a 99% confidence interval for the percentage of all Americans who believe they have seen a ghost. Interpret your interval. Round to three decimal places.

A poll conducted in 2012 asked a random sample of 1358 adults in the United States...

A poll conducted in 2012 asked a random sample of 1358 adults in the United States how much confidence they had in banks and other financial institutions. A total of 149 adults said that they had a great deal of confidence. An economist claims that less than 13% of U.S. adults have a great deal of confidence in banks. Can you conclude that the economist's claim is true? Use both α=0.10 and α=0.01 levels of significance and the P-value method...

Confidence in banks: A poll conducted in 2012 asked a random sample of 1342 adults in...

Confidence in banks: A poll conducted in 2012 asked a random sample of 1342 adults in the United States how much confidence they had in banks and other financial institutions. A total of 143 adults said that they had a great deal of confidence. An economist claims that less than14% of U.S. adults have a great deal of confidence in banks. Can you conclude that the economist's claim is true? Use both =α0.10 and =α0.01 levels of significance and the...

n a recent poll, a random sample of adults in some country (18 years and older)...

n a recent poll, a random sample of adults in some country (18 years and older) was asked, "When you see an ad emphasizing that a product is "Made in our country," are you more likely to buy it, less likely to buy it, or neither more nor less likely to buy it?" The results of the survey, by age group, are presented in the following contingency table. Complete parts (a) through (c). Purchase likelihood 18 dash 3418-34 35 dash...

In May 2015, a poll asked a random sample of 1,089 American adults the following question....

In May 2015, a poll asked a random sample of 1,089 American adults the following question. "Thinking about how the abortion issue might affect your vote for major offices, would you only vote for a candidate who shares your views on abortion or consider a candidate's position on abortion as just one of many important factors or not see abortion as a major issue?" It found that 21% of respondents said they will only vote for a candidate with the...

A simple random sample of 1088 adults between the ages of 18 and 44 is conducted....

A simple random sample of 1088 adults between the ages of 18 and 44 is conducted. It is found that 274 of the 1088 adults smoke. Use a 0.05 significance level to test the claim that less than one-fourth of such adults smoke. Use P-value approach and determine conclusion. Select one: a. P-value = 0.889, fail to reject the alternative hypothesis b. P-value = 0.444, fail to reject the null hypothesis c. P-value = 0.444, reject the null hypothesis d....

In a recent survey conducted by the Pew Research Center, a random sample of adults 18...

In a recent survey conducted by the Pew Research Center, a random sample of adults 18 years of age or older living in the continental united states was asked their reaction to the word socialism. In addition, the individuals were asked to disclose which political party they most associate with. Results of the survey are given in the table. Democrat Independent Republican Positive 220 144 62 Negative 279 410 351 a) Explain why this data should be analyzed by the...

In a recent survey conducted, a random sample of adults 18 years of age or older...

In a recent survey conducted, a random sample of adults 18 years of age or older living in a certain country were asked their reaction to the word socialism. In addition, the individuals were asked to disclose which political party they most associate with. Results of the survey are given in the table. Complete parts (a) through (c) below. _ Democrats Independents Republicans Positive 216 64 158 Negative 270 370 411 (a) Does the evidence suggest individuals within each political...

Confidence Intervals. A Gallup Poll conducted from December 5 to 8, 2013, asked a random sample...

Confidence Intervals. A Gallup Poll conducted from December 5 to 8, 2013, asked a random sample of 1031 adults to rate the honesty and ethical standards of people in a variety of professions. Among the respondents, 406 rated the honesty and ethical standards of TV reporters as very high or high. Assume that the sample was an SRS. A) Give a 95% confidence interval for the proportion of all adults who would rate the honesty and ethical standards of TV...

In a recent Gallup poll, 507 adults aged 18 and older were surveyed and 269 said...

In a recent Gallup poll, 507 adults aged 18 and older were surveyed and 269 said they believed they would not have enough money to live comfortably in retirement. Use a 0.01 significance level to test the claim that the proportion of adults who do not believe they will have enough money to live comfortably in retirement is smaller than 60%. The test statistic is?: ["-2.73", "-3.19", "-3.55", "-4.21", "-1.61"] The p-value is?: ["0.0002", "0.0024", "0.0032", "0.0007", "0.0001"] Based on...

Subjects