(a) There are many situations in which we want to compare means from populations having standard deviations that are equal. This method applies even if the standard deviations are known to be only...

Extracted text: (a) There are many situations in which we want to compare means from populations having standard deviations that are equal. This method applies even if the standard deviations are known to be only approximately equal. Consider a report regarding average incidence of fox rabies in two regions. For region I, n, = 14, x, = 4.75, and s, = 2.84 and for region II, n2 = 13, x2 = 3.95, and sz = 2.41. The two sample standard deviations are sufficiently close that we can assume o, = 0,. Use the method of pooled standard deviation to consider the report, testing if there is a difference in population mean average incidence of rabies at the 5% level of significance. (Round your answer to three decimal places.) It =