Question

The piston diameter of a certain hand pump is 0.7 inch. The manager determines that the diameters are normally​ distributed, with a mean of 0.7 inch and a standard deviation of 0.003 inch. After recalibrating the production​ machine, the manager randomly selects 23 pistons and determines that the standard deviation is 0.0021 inch. Is there significant evidence for the manager to conclude that the standard deviation has decreased at the alpha equals 0.10 level of​ significance? Use technology to determine the​ P-value for the test statistic. The​ P-value is ​(Round to three decimal places as​ needed.)

Answer 1