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Chapter 8: Q. 49 (page 498)

49. A Gallup Poll found that only 28%of American adults expect to inherit money or valuable possessions from a relative. The poll鈥檚 margin of error was 卤3percentage points at a 95% confidence level. This means that
(a) the poll used a method that gets an answer within 3%of the truth about the population 95% of the time.
(b) the percent of all adults who expect an inheritance is between 25%and 31%.
(c) if Gallup takes another poll on this issue, the results of the second poll will lie between 25%and 31%.
(d) there鈥檚 a 95% chance that the percent of all adults who expect an inheritance is between 25% and 31%.
(e) Gallup can be 95%confident that between 25% and 31% of the sample expect an inheritance

Short Answer

Expert verified

The option (a) is correct.

(a) the poll used a method that gets an answer within 3%of the truth about the population 95%of the time.

Step by step solution

01

Given information

The poll鈥檚 margin of error was 卤3percentage points at a 95% confidence level. To determine the correct option from the given statement.

02

Explanation

(a) The confidence level technique indicates that the true population proportion is within 3% points of the sample mean.
As a result, the statement is correct.
(b) Only a 95%confidence level can guarantee that the population percentage is between 25and 31.
As a result, the statement is false.
(c) Confidence intervals fluctuate depending on the sample.
As a result, the statement is false.
(d) Either 0or 1is the probability. Since the population percentage is between 25and 31percent at the 95% confidence level.
As a result, the statement is false.
(e) The sample has a confidence level of 100%that expects an inheritance between 25and 31 percent .
As a result, the statement is false.
As a result, the right option is (a).

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