The diameters of a wooden dowel produced by a new machine are normally distributed with a mean of 0.55 inches and a standard deviation of 0.01 inches. What percent of the dowels will have a diameter greater than 0.57?

Answer 1

That would be greater than two standard deviations from the mean.

You need a computation tool or table for the "error" or normal distribution function.

Using http://psych.colorado.edu/~mcclella/java/normal/accurateNormal.html , I get 2.3%

For more ab9out the subject, see
http://en.wikipedia.org/wiki/Standard_deviation