Given these assumptions, we know the following. 1  The expected value of the difference between all possible sample means is equal to the difference between population means. 2  Thus, E(x 1 - x 2) = Î¼ d = Î¼ 1 - Î¼ 2. 3  The standard deviation of the difference between sample means (Ï d) is approximately equal to:
Guide to Joplin weather in December. The average maximum daytime temperature in Joplin in December is a cool 8Â°C (46Â°F). The average night-time temperature is usually a very cold -3Â°C (27Â°F). There are usually 5 hours of bright sunshine each day, which represents 51% of the 10 hours of daylight.
Joplin, Missouri. Joplin (/ËdÊÉplÉªn/) or (/ËÊÉplÉªn/) is a city in southern Jasper County and northern Newton County in the southwestern corner of the U.S. state of Missouri. Joplin is the largest city in Jasper County, though it is not the county seat (the county seat is Carthage). As of the 2010 census, the city population was 50,150.