Question

The personnel department of a large corporation wants to estimate the family dental expenses of its employees to determine the feasibility of providing a dental insurance plan. A random sample of 12 employees reveals the following family dental expenses (in dollars): 115 370 250 593 540 225 117 425 318 182 275 228 Construct a 95% confidence interval for the average family dental expenses for all employees in this corporation.

Place your LOWER limit, in dollars rounded to 1 decimal place, in the first blank. Do not use a dollar sign, a comma, or any other stray mark. For example, 123.4 would be a legitimate entry. Place your UPPER limit, in dollars rounded to 1 decimal place, in the second blank. Do not use a dollar sign, a comma, or any other stray mark. For example, 567.8 would be a legitimate entry. Lower Limit Upper Limit

Answer 1

Use TI 84 calculator

STAT --> EDIT --> entering the data into list L1

Now, follow the steps

STAT --> TESTS --> TInterval

Inpt : Data

List : L1

Freq: 1

C-level : 0.95

Press Enter, this gives

Lower limit = 205.5

Upper limit = 400.8