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A Gallup poll included 1012 randomly selected adults who were asked whether "cloning of humans should or should not be allowed." Results showed that 901 of those surveyed indicated that cloning should not be allowed.

(a) Construct a 98% confidence interval estimate of the proportion of adults believing that cloning of humans should not be allowed.

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Final answer:

To estimate the proportion of adults who believe human cloning should not be allowed with 98% confidence, calculate the sample proportion, find the z-score for the desired confidence level, compute the margin of error, and determine the confidence interval by adding and subtracting the margin of error from the sample proportion.

Step-by-step explanation:

To construct a 98% confidence interval estimate of the proportion of adults believing that cloning of humans should not be allowed, we can use the formula for the confidence interval of a proportion, which is given by:

p ± z * √(p(1 - p) / n), where:

  • p is the sample proportion
  • z is the z-score corresponding to the desired confidence level
  • n is the sample size

In this case, the sample proportion (p) is 901/1012, which is the number of adults who said cloning should not be allowed divided by the total number surveyed. The z-score for a 98% confidence level is approximately 2.33 (found in z-score tables or using statistical software). The sample size (n) is 1012.

Substituting these values into the formula, we calculate our confidence interval.

  1. Calculate the sample proportion: p = 901/1012
  2. Find the z-score for a 98% confidence level: z = 2.33
  3. Calculate the standard error: SE = √(p(1 - p) / n)
  4. Multiply the standard error by the z-score: Margin of Error (MOE) = z * SE
  5. Add and subtract the MOE from the sample proportion to find the interval: p ± MOE

After performing these calculations, we have a 98% confidence interval that provides an estimate of the true proportion of adults who believe cloning should not be allowed.

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