Question

A researcher wanted to study the effect of alcohol on reaction time. She hypothesized that alcohol will INCREASE reaction time (participants will take longer to react). She selected a sample of n= 36 participants from Rutgers University. The 36 participants each consumed a 6-ounce glass of wine. Thirty minutes later, the researcher measured each participant’s reaction time, using a standardized driving simulation task for which the regular population has a µ = 400 msec reaction time with a σ = 48. The reaction time mean for the sample was M= 412 msec. Are the data sufficient to conclude that the alcohol significantly increased reaction time?

1. Name the population: ____________________________________

2. Name the sample: ________________________________

3. Cause-What is the independent variable? ___alcohol/ wine________________

4. Effect-What is the dependent variable? ____standardized driving simulation task ____________________

5. What is the appropriate hypothesis test? __________________

6. What two means are you comparing in this test? _____________________________

7. Please calculate the appropriate hypothesis test using all four steps:

Answer 1

(1)

Name the population :

All persons from Rutgers University.

(2)

Name the sample

a sample of n= 36 participants from Rutgers University.

(3)

Cause-What is the independent variable?

alcohol

(4)

Effect-What is the dependent variable?

reaction time

(5)

Z Test for One Population Mean

(6)

What two means are you comparing in this test?

= Population Mean = 412

= Hypothesized Population Mean = 400

(7)

Please calculate the appropriate hypothesis test using all four steps:

Step 1:

H0: Null Hypothesis: ( the alcohol did not significantly increase reaction time )

HA: Alternative Hypothesis: ( the alcohol significantly increased reaction time ) (claim)

Step 2:

Take = 0.05

One Tail Right Side Test

From Table critical value of Z = 1.64

Rejection Region:
Reject H0 if Z > 1.64

Step 3:

Test Statistic is given by:

Step 4:

Since calculated value of Z = 1.50 is less than critical value of Z = 1.64, the difference is not significant. Fail to reject null hypothesis.

Conclusion:

The data do not support the claim that the alcohol significantly increased reaction time.