Question 563550
*[tex \LARGE |\frac{h-50}{5}| < 1.645] implies *[tex \LARGE -1.645 < \frac{h-50}{5} < 1.645]


Multiply by 5


*[tex \LARGE -8.225 < h-50 < 8.225]


*[tex \LARGE 41.775 < h < 58.225]


Range is approximately 42 < h < 58.


B: Since 40 lies out of the range, it is very unlikely that 40/100 heads would have occurred by chance. Therefore you have reason to reject the hypothesis that the coin is not fair (with ~90% confidence).