A locomotive's "adhesion" is the locomotive's pulling force as a multiple of its weight. This is an important performance measure of a locomotive. A diesel locomotive model has adhesion that varies in actual use according to a Normal distribution with mean of 0.37 and standard deviation of 0.04.
The percent of adhesions measured in use that are higher than 0.40 is closest to?
A Normal density curve has which of the following properties?
- It is symmetric.
- It has a peak centered above its mean.
- The spread of the curve is proportional to the standard deviation.
- All of the above