an educational testing company has been using a standard test of verbal ability and the mean and standard deviation have been 430 and 130...

an educational testing company has been using a standard test of verbal ability and the mean and standard deviation have been 430 and 130 respectively. in analyzing a new version of the test, it is found that a sample of 20 randomly selected subjects process a mean and standard deviation of 424 and 155 respectively. at the .05 level of significance, test the claim that the new version has standard deviation equal to that of the past version