Originally Posted by

**Rugrats3**
The questions regarding confidence intervals and population means are hard to understand: Please help me set them up in a formula and solve.

#3 An inspector has been given the assignment to estimate the mean net weight og pakages of beef labeled 3 pounds. He realizes that the weights cannot be precisely 3 pounds. A sample of 36 packages reveal the mean weight to be 3.01 pounds, with a standard deviation of 0.03 pounds.

a. What is the estimated population mean?

b. Determine a 95 percent confidence interval for the population mean?

#4 The HR Department would like to include a dental plan for the benefits package. How much does a typical employee and his or her family spend per year on dental expenses? A sample of 45 employees reveals the mean amount spent last year was $1,820, with a standard deviation of $660.

a. Construct a 95% confidence interval for the population mean.

b. The information from part (a) was given to the president. He indicated he could afford $1,700 of dental expenses per employee. Is it possible that the population mean could be $1,700? Why?