Question

The provincial governments are concerned with ruptures in towns (defined as being smaller that cities). For a certain category of town size, namely medium sized, ruptures occur at an average rate of 1 rupture per 200 town-years (if one is focusing on 1 of these towns, this implies that ruptures occur on average once every 200 years, if focusing on 10 such towns the rate will be increased by 10-fold). Assume that in the province of Ontario there are 800 such towns, and let the random variable X represent the number ruptures in a year occuring in the 800 medium sized towns. Calculate:

(a) (1 point) The expected value for X

(b) (1 point) The standard deviation for X

(c) (1 point) The coefficient of variation for X

(d) (2 points) The probability that 4 or more ruptures occur in that year

Answer 1