To study the average weight difference between different races, we collected 36 male adults weights from Asian, and another 36 from European. The sample mean are 156 lb and 167 lb. Let's assume the population standard deviation of Asian male adult weight and European male adult weight are 20 lb, 25 lb, respectively.

P-value method to test if the average weight of two races are different. Let=0.1.

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2.Calculate 95% two-sided confidence interval for the mean weight difference.