Question

For each of the following statements, list the independent and dependent variables, and give the research hypothesis and the null hypothesis.

An official at the state transportation office thinks that switching over from manual to automated toll collection will decrease administrative costs, and asks you to do a survey of other states costs and collection practices to determine if this is true.

The local firefighter’s union in your town claims that its salaries are lower than those of firefighters in other towns.

A legal advocacy group charges that local cops are pulling over Black drivers at higher rates than White drivers.

A official claim that the recent decrease in crime can be attributed to the city’s new neighborhood watch program

Answer 1

For each of the following statements, list the independent and dependent variables, and give the research hypothesis and the null hypothesis.

Statement 1

An official at the state transportation office thinks that switching over from manual to automated toll collection will decrease administrative costs, and asks you to do a survey of other states costs and collection practices to determine if this is true.

Independent variable: Toll collection method (Manual or Automated)

Dependent variable: Administrative cost

Null hypothesis: H₀: Switching over from manual to automated toll collection do not decreases the administrative costs.

Research or alternative hypothesis: H_a: Switching over from manual to automated toll collection decreases the administrative costs.

Statement 2

The local firefighter’s union in your town claims that its salaries are lower than those of firefighters in other towns.

Independent variable: City

Dependent variable: Salary

Null hypothesis: H₀: There is no significant difference in the average salaries of local firefighter’s and average salaries of firefighters in other towns.

Research or alternative hypothesis: H_a: The average salaries of local firefighters are significantly lower than those of firefighters in other towns.

Statement 3

A legal advocacy group charges that local cops are pulling over Black drivers at higher rates than White drivers.

Independent variable: Race of driver

Dependent variable: Rate

Null hypothesis: H₀: A legal advocacy group charges that local cops are pulling over Black drivers at same rates as that for White drivers.

Research or alternative hypothesis: H_a: A legal advocacy group charges that local cops are pulling over Black drivers at higher rates than White drivers.

Statement 4

A official claim that the recent decrease in crime can be attributed to the city’s new neighborhood watch program

Independent variable: Neighborhood watch program

Dependent variable: Crime rate

Null hypothesis: H₀: There is no any significant decrease in crime due to city’s new neighborhood watch program.

Research or alternative hypothesis: H_a: There is a significant decrease in crime due to city’s new neighborhood watch program.