Practice Problem ANSWERS: t-Test

 

#1

Calculate am independent t-test for the following data:

X₁            X₂
6             12
4               4
2               7
3             10
9               5
6               8
5               3

Mean of group 1        5

Mean of group 2       7

Difference between the means   2

SS of group 1           32

SS of group 2           64

n(n-1)                      42

t = 1.32

How many degrees of freedom (df) at in this study   N-2 = 12

What is the critical value for t (2 tailed, .05 alpha)      2.18

Is the t significant       No. The calculated value (1.32) is not equal to (or bigger) that the critical value (2.18). The differences between the groups is likely to be due to chance.

 

 

#2

Calculate am independent t-test for the following data:

X₁            X₂
15          3
11          5
  8          4
12          2
  7          6

 

Mean of group 1     10.60

Mean of group 2      4.00

SS of X1     41.20

SS of X2    10

t =   4.13

 

 

#3

Calculate am independen t-test for the following data:

X₁              X₂
  6           3
  7           5
  6           3
  8           2
  4           7
11           4 

 

t = 2.48

How many degrees of freedom (df) at in this study     10

What is the critical value for t (2 tailed, .05 alpha)       2.23

Is the t significant? Yes

 

NOW YOU CHOOSE:
    Day 8: Student’s t-Test
    Bit More About t-Test
    Even More About t-Test
    How to Calculate t-Test
    Practice Problems
    More Practice Problems
    Word Problems
        Sim1           Sim2            Sim3
        Sim4           Sim5            Sim6
        Sim7           Sim8            Sim9
    Basic Facts About t-Test
    Vocabulary
    Formulas
    Quiz 8
    Summary