Sang swam 2,000 meters. Lu ran 3 times farther. How far did Lu run?
2 answers:
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Answer:
C. z = 2.05
Step-by-step explanation:
We have to calculate the test statistic for a test for the diference between proportions.
The sample 1 (year 1995), of size n1=4276 has a proportion of p1=0.384.
The sample 2 (year 2010), of size n2=3908 has a proportion of p2=0.3621.
The difference between proportions is (p1-p2)=0.0219.
The pooled proportion, needed to calculate the standard error, is:
The estimated standard error of the difference between means is computed using the formula:
Then, we can calculate the z-statistic as:
z=2.05