Siscetic

Question 1: The service life of a battery used in a cardiac pacemaker is assumed to be normally distributed. A random sample of 10 batteries is subjected to an accelerated life test by running the, continuously at an elevated temperature until failure, and the following lifetimes (in hours) are obtained: 25.5, 26.1, 26.8, 23.2, 24.2, 28.4, 25.0, 27.8, 27.3, and 25.7. The manufacturer wants to be certain that the mean battery life exceeds 25 hours in accelerated life testing.

Construct a 90% two-sided confidence interval on mean life in the accelerated test.

Question 2: During shipment testing, product was flown from Indianapolis to Seattle and back again to simulate 4 takeoffs and landings which can cause cans to open due to pressure changes. Prototype units of the 100 were shipped and 15 opened. Using a 90% two-sided confidence interval to analyze the situation (use the formula for proportions)

Question 3: An experiment was conducted to investigate the filling capability of packaging equipment at a winery in Newberg, Oregon. Twenty bottles of Pinot Gris were randomly selected and the fill volume (in mL) measured. Assume that fill volume has a normal distribution. The data are as follows: 753, 751, 752, 753, 753, 753, 752, 753, 754, 754, 752, 751 752, 750, 753, 755, 753, 756, 751, and 750.

Do the data support the claim that the variance of fill volume is less than 1 ml using a 95% two-sided confidence interval? =(Construct 95% two sided confidence interval on variance)