The distribution of the heights of students in a large class is roughly normal. Moreover, the average height is 68 inches, and approximately 95% of the heights are between 62 and 74 inches. Thus the standard deviation of the height ...

There are three children in a room, ages three, four, and five. If a four-year-old child enters the room the (a) mean age will stay the same but the variance will increase. (b) mean age will stay the same but the ...

A researcher reports that, on average, the participants in his study lost 10.4 pounds after two months on his new diet. A friend of yours comments that she tried the diet for two months and lost no weight, so clearly ...