Two different computer firms manufacture laptop
computers. Random samples are selected from
each firm and the following data is collected.
Firm A: nA=20
sA=$100 xA = $1500
Firm B: nB=22
sB=$200 xB = $1900
Test the claim that the average price of Firm A’s
laptop is no different from the average price of
Firm B’s laptop
Ho: uA = µB
Ha: uA ≠ uB
X A  X B = difference between the average
price of Firm A’s and Firm B’s laptops
Distribution for the Test: Student-t for the
difference of two means
USE A 2-SampTTest.
Test statistic: t = -8.31
Standardized score for
xA  xB  1500  1900  400
9
p-value: ≈ 0 (1.9394  10 )
Decision: Assume
  0.05 (  p  value)
REJECT H0.
Conclusion: There is sufficient evidence to
conclude that the average price of Firm A’s
laptop is different from the average price of
Firm B’ laptop.