Remember that
z =(x - μ)/σ
where
μ=166.9 min
σ=76.1 min
For x=14.7 min
z1=(14.7-166.9)/76.1
z1=-2
For x=90.8 min
z2=(90.8-166.9)/76.1
z2=-1
Using a z-score table values
we have that
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