Sample mean : \overline{x}=10.6x=10.6
Standard deviation : s=1.7s=1.7
Significance level : \alpha:1-0.95=0.05α:1−0.95=0.05
Critical value : z_{\alpha/2}=1.96
Hence the 95% confidence interval for the number of chocolate chips per cookie for big chip cookies= (10.1989,\ 11.0011)(10.1989, 11.0011)
Subtract original amount from new amount:
84 - 39 = 45
He bought 45 books.
Answer:
33 dollors a hour I think I may be wrong