|
Brand 1 |
Brand 2 |
Difference |
|
36925 |
34318 |
2607 |
|
45300 |
42280 |
3020 |
|
36240 |
35500 |
740 |
|
32100 |
31950 |
150 |
|
37210 |
38015 |
-805 |
|
48360 |
47800 |
560 |
|
38200 |
33215 |
4985 |
Sample mean of the difference using excel function AVERAGE(),
x?d = 1608.1429
Sample standard deviation of the difference using excel function
STDEV.S() sd = 2008.1474
Sample size, n = 7
Null and Alternative hypothesis: µd = Brand 1-Brand
2
Ho : µd = 0
H1 : µd > 0 (claim)
Test statistic:
t = (x?d)/(sd/?n) =
2.1187
df = n-1 = 6
Critical value :
Right tailed critical value, t_c = ABS(T.INV(0.05,6) ) =
1.943
p-value :
Right tailed p-value = T.DIST.RT(2.1187,6) =
0.0392
Decision:
p-value < ?, Reject the null hypothesis.
There is enough evidence to conclude that Brand 1 has a better
mean lifetime at 0.05 significance level.
