A Company in Maryland Has Developed a Device That Can

question 94

Multiple Choice

A company in Maryland has developed a device that can be attached to car engines,which it believes will increase the miles per gallon that cars will get.The owners are interested in estimating the difference between mean mpg for cars using the device versus those that are not using the device.The following data represent the mpg for independent random samples of cars from each population.The variances are assumed equal and the populations normally distributed. Given this data,what is the critical value if the owners wish to have a 90 percent confidence interval estimate?

• A)t = 2.015
• B)t = 1.7823
• C)z = 1.645
• D)z = 1.96

---

Definitions:

Maximum Interference

The largest value by which one part exceeds the size of its mating part, making assembly possible only with the application of force.

Force Fit

A type of interference fit where components are pressed together using high force, resulting in a very tight fit with no movement between parts.

Hole

An opening through a solid body or surface, typically circular.

Allowances

The intentional difference between the maximum material limits of mating parts to ensure a certain type of fit.