What's the difference between calculating confidence interval to determine hypothesis testing via normal confidence interval calculations.

How do I apply the above mentioned principles to get over this challenge?

1. Jamaica Biscuit Corporation sells strawberry cream biscuits in 150g packages with a tolerance of 5%. If their packing machine has a variation greater than this tolerance, then an adjustment needs to be made. They randomly select 15 of their strawberry cream biscuit packages and weighs them. The results are as follows: 158 167 149 169 164 139 154 172 150 157 171 152 161 141 166 Normal Q-Q Plot of Weight 160- Expected Normal Value 140- 150 170 Observed Value HINT: tolerance is another way of expressing variation. It is measured in units and not units. a) Calculate a 99% confidence interval for the variation in the weight of strawberry cream biscuit packages. b) Using the interval you created in (a), determine if the package machine needs to be adjusted. Use the appropriate level of significance. c) Based on the information presented, do you have any concerns about the confidence interval created in (a)? Give reasons for your