3. a. A product designer wants to determine the average amount of time it takes to assemble a toy. A sample study data of 16 times toy assembly showed an average assembly time of 14.64 minutes, with a standard deviation of 5.82 minutes. Assuming sample data is normally distributed, provide a 95% & 99% confidence interval for the mean assembly time (Z0.95 = 1.645). What would happen to the confidence interval, in case #samples selected for the study are increased?  (15 Marks) 

The above question contains 15 Marks. As per University guidelines, the answer should be a min of 500 words. So please I am requesting you please prepare as per guidelines.