Population mean = (14,44)
Z at 99.7% = 2.96
Therefore,
Sample mean = (14+44)/2 = 29
However,
Population mean = Sample mean +/- Z*s/Sqrt (n)
Taking one of the ranges, say lower range:
14 = 29-Z*s/Sqrt (n)
14-29 = - 2.96*s/Sqrt (n)
-15 = -2.96*s/Sqrt (n)
5 = s/Sqrt (n)
Therefore,
[tex] \frac{s}{ \sqrt{n} } = 5[/tex]