After years of rapid growth, illegal immigration into the United States has decl
ID: 3050822 • 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 31% of the nation’s estimated 17.9 million undocumented immigrants. Use Table 1.
In a sample of 70 illegal immigrants, what is the probability that more than 20% live in California?(Round “z” value to 2 decimal places, and final answer to 4 decimal places.)
In a sample of 250 illegal immigrants, what is the probability that more than 20% live in California? (Round “z” value to 2 decimal places, and final answer to 4 decimal places.)
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 31% of the nation’s estimated 17.9 million undocumented immigrants. Use Table 1.
Explanation / Answer
Ans:
a)standard deviation=sqrt(0.31*(1-0.31)/70)=0.0553
z=(0.2-0.31)/0.0553=-1.99
P(z>-1.99)=P(z<1.99)=0.9767
b)standard deviation=sqrt(0.31*(1-0.31)/250)=0.0293
z=(0.2-0.31)/0.0293=-3.76
P(z>-3.76)=P(z<3.76)=0.9999