After years of rapid growth, illegal immigration into the United States has decl
ID: 3052253 • Letter: A
Question
After years of rapid growth, illegal immigration into the United States has declined, perhaps owing to the recession and increased border enforcement by the United States (Los Angeles Times, September 1, 2010). While its share has declined, California still accounts for 27% of the nation’s estimated 12.8 million undocumented immigrants. Use Table 1.
a. In a sample of 50 illegal immigrants, what is the probability that more than 21% live in California? (Round intermediate calculations to 4 decimal places, “z” value to 2 decimal places, and final answer to 4 decimal places.) Probability
b. In a sample of 180 illegal immigrants, what is the probability that more than 21% live in California? (Round intermediate calculations to 4 decimal places, “z” value to 2 decimal places, and final answer to 4 decimal places.) Probability c.
c. Comment on the reason for the difference between the computed probabilities in parts a and b.
A) As the sample number increases, the probability of more than 21% also increases, due to the increased z value and decreased standard deviation
B) As the sample number increases, the probability of more than 21% also increases, due to the increased z value and increased standard deviation
Explanation / Answer
a)
probability that more than 21% live in California :
b)
c)
option A is correct
As the sample number increases, the probability of more than 21% also increases, due to the increased z value and decreased standard deviation
for normal distribution z score =(p-p)/p here population proportion= p= 0.270 sample size =n= 50 std error of proportion=p=(p*(1-p)/n)= 0.0628