The magnitude of most earthquakes is measured on the Richter scale. It was invented by Charles F. Richter in 1934. For example, using this scale, a magnitude 5-5.9 is termed as a moderate earthquake (slight damage to buildings and other structures). Suppose the magnitudes of earthquakes in a region of Indonesia can be modelled with a mean of 4. Find the probability that the next earthquake to hit this region will exceed 4 on the Richter scale.