Statistics - Hypothesis Testing Projects

QUESTION ONE It is hypothesized that overweight individuals are more intelligent than slim individuals.

QUESTION ONE

It is hypothesized that overweight individuals are more intelligent than slim individuals. In order to test this hypothesis, a group of 11 overweight people and 13 slim people were given an IQ (intelligence) test. The IQ scores for the two groups are given below.

Group 1 Overweight individuals	Group 2 Slim individuals
106	109
95	105
91	99
101	95
102	110
98	106
92	108
102	105
100	101
97	100
	101
	98

You will need to do the following:

1.1 Produce descriptive statistics and normality information for the two groups.

1.2 Carry out the appropriate statistical test to test the hypothesis.

1.3 Check that the assumptions of the test have been met.

1.4 COMPLETE the following.

GROUP 1 Mean______________ Std. Dev._________

GROUP 2 Mean_______________ Std. Dev._____________

1.5 Are the distributions of the data in each of the two groups normally distributed.

DESCRIBE the distributions.

1.6 WHICH statistical test should you use to analyse the differences between the two groups? EXPLAIN the reasons for your choice (include comments about whether the assumptions of the test were met or not.

1.7

The result of the statistical test is t =________, df = ________and p = _______

1.8

STATE your conclusions in words.

QUEST IO N TWO

It is hypothesized that first year students, second year students and third year students will all get different results on the same pathology test. In order to test this hypothesis , groups of first, second, and third year students wrote the same pathology examination. The test scores for the three groups of students are given below.

Group 1 First year students	Group 2 Second year students	Group 3 Third year students
24	17	16
17	20	11
30	23	13
15	25	10
21	20	16
28	16	9
20	25
30

2.1 Provide the descriptive statistics for the three groups.

2.2 Carry out the appropriate statistical tests to test the hypothesis.

2.3 Check that the assumptions of the test have been met

2.4 STATE the following for each group.

GROUP 1 Mean_________________ Std.Dev._____ _______

GROUP 2 Mean____________ Std.Dev.______ _____________

GROUP 3 Mean__________________ Std.Dev._____ ____________

2.5 WHICH statistical test should you use to analyse the differences between the 3 groups?

EXPLAIN the reasons for your choice of answer (include comments about whether the assumptions of the test were met).

2.6.

The result of the statistical test is F = _____, df = ________, p = __________

2.7

EXPLAIN your conclusion in words.

Q UESTION 3.0

It is hypothesized that people take longer to brush their teeth at night than in the morning. In order to test this hypothesis, a single group of 14 adults was asked to brush their teeth in the morning , and again at night. The amount of time (in seconds) that it took the individuals to brush their teeth are given below.

subject	Condition 1 morning brushing times	Condition 2 Night brushing times
1	34	38
2	22	29
3	27	37
4	30	40
5	27	36
6	32	32
7	43	38
8	37	36
9	29	35
10	26	33
11	16	34
12	31	24
13	26	38
14	27	37

3.1 Provide the descriptive statistics for the three groups.

3.2 Carry out the appropriate statistical tests to test the hypothesis.

3.3 Check that the assumptions of the test have been met

3.4 STATE the following for each condition.

Condition 1 Mean_____________ Std.Dev._____________

Condition 2 Mean__________ Std.Dev.__________________

3.5 WHICH statistical test should you use to analyse the data?

EXPLAIN the reasons for your choice of answer (include comments about whether the assumptions of the test were met).

Solution: Since the data are paired, we need to use a paired samples t-test.

3.6.

The result of the statistical test is t = _______, df = ________, p = _________

3.7

EXPLAIN your conclusion and comments in words.

3.8 CONVERT the times in seconds into times in minutes using the compute command. (tip: you will need to divide the original times by 60). Call the new variables moningmin and nightmin.