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Homework answers / question archive / The makers of a smartphone have received complaints that the face recognition tool often doesn't work, or takes multiple attempts to finally unlock the phone
The makers of a smartphone have received complaints that the face recognition tool often doesn't work, or takes multiple attempts to finally unlock the phone. They've upgraded to a new version and are claiming the tool has improved. To test the claim, a critic takes a random sample of 80 users of the new version (Group 1) and 75 users of the old version (Group 2). He finds that the face recognition tool works on the first try 75% of the time in the new version and 60% of the time in the old version. Can it be concluded that the new version is performing better? Test at α=0.10.
Hypotheses:
H0: p1 = p2
H1: p1 > p2
In this scenario, what is the test statistic? Round to four decimal places.
z =_______
Answer:
Z statistics =1.99642
Step-by-step explanation
p1(hat)=0.75
n1= 80
p2(hat)=0.6
n2= 75
pooled sample proportion is
?P=n1?+n2?p1??n1?+p2??n2???
=?P=80+750.75∗80+0.6∗75??
p= 0.677419355
standard error of the test:
?SE=P∗Q(n1?1?+n2?1?)??
?SE=0.677∗(1−0.677)(801?+751?)??
SE= 0.0751
Z= (P1-P2)/SE
=(0.75-0.6)/0.0751
=1.99642