In: Statistics and Probability
A national study report indicated that 19.9% of Americans were identified as having medical bill financial issues. What if a news organization randomly sampled 400 Americans from 10 cities and found that 90 reported having such difficulty. A test was done to investigate whether the problem is MORE SEVERE among these cities. What is the p-value for this test?
A) 0.096
B) 0.054
C) 0.216
D) 0.108
Solution:
Given:
A national study report indicated that 19.9% of Americans were identified as having medical bill financial issues.
that is: p = 0.199
Sample size = n = 400
x = Number of Americans reported having such difficulty.= 90
We have to test whether the problem is MORE SEVERE among these cities.
thus hypothesis are:
H0: p = 0.199 Vs H1: p > 0.199 ( this is right tailed ( > ) test)
We have to find P-value:
For right tailed test , p-value is:
p-value = P(Z > z test statistic)
where
where
thus
thus we get:
P-value = P( Z > z )
P-value = P( Z > 1.30245)
P-value = 1 - P( Z < 1.30245)
Use following Excel command to find P-value:
=1-NORM.S.DIST(z,cumulative)
=1-NORM.S.DIST(1.30245,TRUE)
=0.0963813
=0.096
P-value = 0.096
Thus correct answer is:
A) 0.096