= The level of cholesterol in the blood for all men aged 20 to 34 follows a Normal distribution with mean M 188 milligrams per deciliter (mg/dl) and standard deviation M = 41 mg/dl. For 14-year-old boys, blood cholesterol levels follow a Normal distribution with mean B = 170 mg/dl and standard deviation B = 30 mg/dl. Suppose we select independent SRSS of 25 men aged 20 to 34 and 36 boys aged 14 and calculate the sample mean cholesterol levels XM and XB. What is the probability of getting a difference in sample means XM - XB that's less than 0 mg/dl? Round to 4 decimal places.