 Two sample Z test for proportions using Excel This is a typical problem and a survey of 460 drivers from the south 394 where seat belt and a survey of 380 out drivers from the north 293 where seat belt at alpha equals zero point zero six Can you support the claim that the proportion of drivers who wear seat belts is greater in the south than in the north? And we're to assume the random samples are independent you always start by stating the null and alternative hypothesis Here in math forms the claim was that the proportion in the south is greater than the proportion in the north The alternative that thus is ha P1 greater than P2 The null has to be the complement P1 less than or equal to P2 and again ha is the claim Because the claim the alternative has a greater than symbol that points to the right that tells you this is a right tail test Excel does not have a built-in test for the two sample Z test proportions So you have to construct one manually instead of doing that though in your Calculator package in this assignment. You will find a number of Calculators, this is the two samples Z test for proportions with X given. There's another version of it in which you are given the Proportions in the samples, but in this example We were given the counts the X's You enter your X and ends in the blue cells. You enter your Significance level whenever you're running a Z test proportions You have to check to make sure there's a normal approximation is Appropriate this calculator does that automatically and here you can see that all of the required checks Come up green which means we can proceed with the test the calculator gives us our Sample proportions p hat one and p hat two and also our estimates of the population proportions and one minus P q which you need to solve this It gives us a test statistic of the difference in the sample proportions of 0.855 Standardizes that test statistic to 3.194 then you have to make a decision and The calculator will give you the critical values for the two tail left tail and right tail test Here, this is a right tail test So the upper critical value is calculated as 1.55 and if you compare that with the standardized test statistic you can see that the Standardized test statistic falls well to the right of the critical value that would tell you to reject the null We also have a p-value of point zero zero zero seven which is much less than our alpha of a point zero six That also tells you to reject the null