Question

For this assignment, use data from W1 Assignment.

Compute a t-test comparing males' and females' heights. You must determine which type of t-test to compute.

Move your output into a Microsoft Word document and write a one-paragraph, APA-formatted interpretation of the results.

Participant ID   Age   Sex   Height   Year in college  
1   18   f   60   freshman  
2   17   f   61   freshman  
3   18   f   62   freshman  
4   18   f   63   freshman  
5   23   f   66   freshman  
6   25   m   65   freshman  
7   22   m   66   freshman  
8   21   m   68   freshman  
9   37   m   69   freshman  
10   32   m   72   freshman  
11   19   f   70   sophomore  
12   20   f   60   sophomore  
13   33   f   61   sophomore  
14   22   f   60   sophomore  
15   23   f   65   sophomore  
16   20   m   67   sophomore  
17   21   m   67   sophomore  
18   22   m   65   sophomore  
19   27   m   70   sophomore  
20   29   m   71   sophomore  
21   20   f   61   junior  
22   21   f   63   junior  
23   33   f   64   junior  
24   37   f   64   junior  
25   24   f   65   junior  
26   24   m   68   junior  
27   26   m   67   junior  
28   31   m   69   junior  
29   28   m   70   junior  
30   33   m   64   junior  
31   21   f   63   senior  
32   23   f   66   senior  
33   28   f   67   senior  
34   29   f   68   senior  
35   52   f   62   senior  
36   43   m   72   senior  
37   32   m   70   senior  
38   28   m   69   senior  
39   29   m   67   senior  
40   40   m   65   senior  

Answer 1

Two sample t test is used to compare the means heights of males and females assuming equal variance.

The test is performed in following steps,

Step 1: The Null and Alternative Hypotheses

Step 2: The t statistic is used to compare the two population means and the significance level for the test is

The decision rules state the conditions that if,

,

Step 3: The t statistic is obtained using the formula,

From the samples data value, the mean and standard deviation for each male and female are obtained in excel using the function =AVERAGE() and STDEV() respectively.

	Male	Female
Mean	68.05	63.55
SD	2.3725	2.8373
n	20	20

Step 4:

The P-value for the t statistic is obtained from t distribution table for degree of freedom = n1+n2-2=20+20-2=38

The corresponding P-value is 0.0000 which is less than 0.05 at the 5% significance level for the two sided alternative hypothesis. It can be concluded that the null hypothesis is rejected. Hence, there is significant difference in means heights of males and females