we need to determine P (x> 73)
when
mean: μ = 74 beats/min
standard deviation: σ = 2 beats/min
First we need to use the following formula:
where
x = 73
μ = 74
σ = 2
and
Z is the z-score
... therefore
If we check a table of z scores, we will find that when z = -0.5, then P = 0.3085
Now, since we need P(x>73)
therefore
P(x>73) = 0.6915