1. ## stopwatch_normal_help

a manually operated stopwatch is used to clock times in a 100 m track race. if the true time of a runner is t, the watch will show time t+0.1+X, where X has a normal distribution with expected value 0 and variance 0.01.
(a) for a given t, what is the distribution of T?
(b) if the true time t is 15 seconds, what is P(T<=11.5)?
(c) what is the probability that T is within 0.05 seconds of the true time t?

2. Originally Posted by anzej
a manually operated stopwatch is used to clock times in a 100 m track race. if the true time of a runner is t, the watch will show time t+0.1+X, where X has a normal distribution with expected value 0 and variance 0.01.
(a) for a given t, what is the distribution of T?
(b) if the true time t is 15 seconds, what is P(T<=11.5)?
(c) what is the probability that T is within 0.05 seconds of the true time t?
(a) Use property 1 from here: Normal distribution - Wikipedia, the free encyclopedia

Knowing the distribution of T, you should now ba able to do (b) and (c).

3. Appreciate your help mr fantastic.

Thanks a lot