Math 135 Statistics

Establishing Hypotheses

  1. A researcher thinks mice will run faster through a maze if a loud noise is applied. The average completion time for the mice without the noise applied is 18 seconds. 10 mice are sent through the maze and the noise is applied each time.

Ho: Noise has no effect. The average completion time is the same as before. (= 18 seconds)

Ha: Noise has an effect. The average completion time is less than before. ( 18 seconds)

  1. The census bureau says that households spend an average of 29% of income on housing. You want to see if your neighborhood is different from the national average.

Ho: ______

Ha: ______

  1. A company that sells office copiers produces a copier that currently has an average life span of 8 years. A technician who works for the company thinks that if a new part is added to the copier, the average life span will increase.

Ho: ______

Ha: ______

  1. Based on a poll from last year, the estimated number of people who favored the establishment of national health insurance was 60%. A new ad campaign has been generated by the Republican party that is intended to “attack” the idea of national health insurance. The Republican party wants to test to see if the new percent who favor national health insurance has changed.

Ho: ______

Ha: ______

  1. Researchers wish to compare the effectiveness of a new drug to treat lung cancer against the current standard treatment.

Ho: ______

Ha: ______

  1. The current average miles per gallon for a certain car model is 30 mpg. A designer suggests a change to the engine construction that she suspects will improve the gas mileage for the car.

Ho: ______

Ha: ______

  1. A process designer for a health insurance company thinks that the creation of a new form will reduce the average number of errors per month for health insurance claims. The current average number of errors per month for the company’s health insurance claims is 20 errors per month.

Ho: ______

Ha: ______