Aresearcher would like to test the claim that 9 out of 10 doctors prefer brand x. a sample of 60 doctors is obtained and each is asked to compare brand x with another leading brand. the data show that 48 of the doctors picked brand x. if these data are evaluated using a chi-square test for goodness of fit, what is the expected frequency for brand x? quizlet

The expected values are 54 prefer X, 6 don't.
   For the chi-square test, you need to calculate the sum of the squared differences between the observed values minus the expected value, divided by the expected value. Since the claim is 9 out of 10, we should have 0.9 * 60 = 54 doctors prefer brand X and the remaining 60-54 = 6 not preferring brand X.

Answer to the problem is: 9 3/10