SOLUTION: Suppise you are told that a 95% confidence interval for the average price of gasoline in your state is from $3.37 to $3.89. Use the fact that the confidence interval for the mean

Algebra ->  Statistics  -> Confidence-intervals -> SOLUTION: Suppise you are told that a 95% confidence interval for the average price of gasoline in your state is from $3.37 to $3.89. Use the fact that the confidence interval for the mean      Log On


   

Question 1060766: Suppise you are told that a 95% confidence interval for the average price of gasoline in your state is from $3.37 to $3.89. Use the fact that the confidence interval for the mean is in the former x -E to x + E to compute the sample mean and the maximal margin of error E
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Suppise you are told that a 95% confidence interval for the average price of gasoline in your state is from $3.37 to $3.89. Use the fact that the confidence interval for the mean is in the former x -E to x + E to compute the sample mean and the maximal margin of error E
Since the LOWER and UPPER LIMITs of the confidence interval are: $3.37, and $3.89, respectively, we can say that:

  x   -  E  =  3.37 ------ eq (i)

  x  +  E  =  3.89 ------ eq (ii)

         2x  =  7.26 ------ Adding eqs (ii) & (i)

          x, or 



3.63 - E = 3.37 ------ Substituting 3.63 for x in eq (i)

        - E = 3.37 - 3.63

        - E = - .26

          E, or