1 That is, the macro generates a random number for each observation, the data set is sorted by the random number, and then the first num observations are selected.  Then, call the macro select three times once for each of the city data sets .... scollege, pmatilda, and bellefnt .... selecting five observations from each.
A humid continental climate is marked by variable weather patterns and a large seasonal temperature variance. Places with more than three months of average daily temperatures above 10 Â°C (50 Â°F) and a coldest month temperature below â3 Â°C (27 Â°F) and which do not meet the criteria for an arid or semiarid climate, are classified as continental.
Continental (Group D) climates are found in most of the North American interior from about 40Â°N to 70Â°N. In this climate, summers are cool-to-warm and winters are very cold and stormy. The average temperature of the warmest month is higher than 10Â°C (50Â°F) and the coldest month is below -3Â°C (-27Â°F).he subpolar climate is found between the humid continental and the polar tundra climates (Figure 17.22). This climate is dominated by long, very cold winters with very little precipitation. Continental polar air masses form when air stagnates in this zone.