Download Probability and Statistics

Probability and Statistics
Name______________________________
HW 2 – Set Up the Null and Alternative Hypotheses
Directions: Identify the null and alternative hypotheses and identify the claim for the
following. Sketch the sampling distribution and shade the area for the tails.
1.
An engineer wants to show that applications of paint made with the new formula dry
and are ready for the next coat in a mean time of less than 30 minutes.
2.
A university claims that the proportion of its students who graduate in four years is
82%.
3.
A water faucet manufacturer claims that the mean flow rate of a certain type of
faucet is less than 2.5 gallons per minute.
4.
A cereal company claims that the mean weight of the contents of its 20-oz size
cereal boxes is more than 20 ounces.
5.
An automobile battery manufacturer claims that the mean life of a certain type of
battery is 74 months.
6.
A television manufacturer claims that its proportion of the local listening audience is
greater than 39%.
7.
A light bulb manufacturer claims that the mean life of a certain type of light bulb is
more than 750 hours.
8.
As stated by a company’s shipping department, the number of shipping errors per
million shipments has a standard deviation that is less than 3.
9.
At least 14% of all homeowners have a home security alarm.
10.
A government report claims the proportion of lung cancer cases that are due to
smoking is 90%.