Objective: Estimate at 95% confidence interval the mean number of production workers by using the manufacturing database.

Justification: Number of production worker is numerical data and are 140 so we will use confidence interval for population mean i.e we will use z-test

Interpretation1 :

The point estimate is sample mean i.e 86.95. The error of the estimation is 22.55 and we are 99% confident that the actual number of the production workers per company is between 64.40 and 109.5

Objective: Estimate at 90% and 99% confidence interval the average census by using the census column from hospital database.

Interpretation 2 : For 99% confidence interval the point estimate (mean) is still same i.e 144.095 because the level of confidence does not change the value of sample mean however the error of estimation increased from 17.47 to 27.50 so we can conclude that as the confidence level increases the normal distribution becomes wider.

Objective: Estimate at 90%, 95% and 99% confidence interval the mean number of earnings per share for database.

Interpretation 3: For 99% confidence interval the point estimate (mean) is still same i.e 2.2466 because the level of confidence does not change the value of sample mean however the error of estimation increased from 0.22 to 0.26 so we can conclude that as the confidence level increases the normal distribution becomes wider.

Objective:

1. Estimate at 95% confidence interval the average census by using the service column from hospital database for the ‘general medical’ category.

2.