In: Statistics and Probability
!!!!!!!!!!!Please explain in detail how you find the answers!!!!!!!!!!!
3. As a further measure for the effectiveness of the medical program, FAU decides to administer the same test to five students in their first year, and then again when they graduate the program: Use the scores below to conduct a t-test and determine whether the scores significantly change over time.
First Year Graduation
85 88
88 93
82 86
92 95
91 96
3B. State the t-statistic and cutoff score (.05-test, 2-tailed) in the t-distribution
3C. Was the test significant?
paired t test
SAMPLE 1 | SAMPLE 2 | difference , Di =sample1-sample2 | (Di - Dbar)² |
85 | 88 | -3 | 1.000 |
88 | 93 | -5 | 1.000 |
82 | 86 | -4 | 0.000 |
92 | 95 | -3 | 1.000 |
91 | 96 | -5 | 1.000 |
b)
mean of difference , D̅ =ΣDi / n =
-4.000
std dev of difference , Sd = √ [ (Di-Dbar)²/(n-1) =
1.000
std error , SE = Sd / √n = 1.0000 /
√ 5 = 0.4472
t-statistic = (D̅ - µd)/SE = ( -4
- 0 ) / 0.4472
= -8.9443
Degree of freedom, DF= n - 1 =
4
α=0.05
t-critical value , t* = ±
2.7764 [excel function: =t.inv.2t(α,df) ]
c)
Decision: test stat < -2.7764 , Reject null
hypothesis
yes, test was significant