Question 1185622
92% half-interval is z(0.96)*3.6/sqrt(120)=1.75*3.6/sqrt(120)=0.575
the interval is (15.625 min, 16.775 min)
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error is the half-interval
so e=z(0.96)(sigma/sqrt(n)), error is 0.25 min
0.25=1.75*3.6/sqrt(n)
square both sides and move n over
0.0625n=39.69
n=635.04 or 636 people