Question

1. The effects of mind-altering products (alcohol intake and medication) on aggressive driving are studied in a group of individuals who drink regularly and take prescription medication. Thirty individuals are assigned based on to their respective groups: either a placebo group (those who do not drink or take medication), medication group (whose members regularly take medication), and alcohol group (whose members regularly drink) who will receive an ounce of alcohol 30 minutes before the driving simulation test is given. The dependent variable is the number of crashes during the 5-minute driving simulation. Determine whether or not there is a significant difference with at least one group. If you reject the null hypothesis, tell what it means in the context of the problem. Include the statistical sentence.

(Use p=.05 or 5%).

Alcohol           Medication     Placebo

10                    7                      5

15                    7                      3

12                    5                      2

8                      8                      4

5                      10                    6                     

21                    13                    5

10                    12                    1

11                    11                    2

13                    11                    5

20                    15                    2

Answer 1

Hypothesis:

Ho : There is a no significant difference with these groups.

V/s

H1 : There is a significant difference with at least one group.

using Excel Data Analysis tool pack

Excel => Data => Data Analysis => Anova: Single Factor => select input range => Labels => output range => ok

Alcohol	Medication	Placebo
10	7	5
15	7	3
12	5	2
8	8	4
5	10	6
21	13	5
10	12	1
11	11	2
13	11	5
20	15	2

Anova: Single Factor
SUMMARY
Groups	Count	Sum	Average	Variance
Alcohol	10	125	12.5	25.16667
Medication	10	99	9.9	9.655556
Placebo	10	35	3.5	2.944444

ANOVA
Source of Variation	SS	df	MS	F	P-value	F crit
Between Groups	429.0667	2	214.5333	17.04148	1.63E-05	3.354131
Within Groups	339.9	27	12.58889
Total	768.9667	29

Here p-value = 0.0000163 or 1.63E-05 < alpha =0.05 then we reject Ho.

Conclusion : with 0.05 level of significance we conclude that ,there is a significant difference with at least one group.