In Greenton, 70\% of the adults own a car. A random sample of 8 adults from Greenton is chosen. A random sample of 120 adults from Greenton is now chosen. Use an approximation to find the probability that more than 75 of them own a car. ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................
Exam No：9709_m20_qp_52 Year：2020 Question No：5(b)
Answer:
Mean \(=120 \times 0.7=84\)
Var \(=120 \times 0.7 \times 0.3=25.2\)
\(P(\) more than 75\()=P\left(z>\frac{75.5-84}{\sqrt{25.2}}\right)\)
\(P(z>-1.693)\)
\(=0.955\)
Var \(=120 \times 0.7 \times 0.3=25.2\)
\(P(\) more than 75\()=P\left(z>\frac{75.5-84}{\sqrt{25.2}}\right)\)
\(P(z>-1.693)\)
\(=0.955\)
Knowledge points:
5.5.3 recall conditions under which the normal distribution can be used as an approximation to the binomial distribution, and use this approximation, with a continuity correction, in solving problems. (n sufficiently large to ensure that both np > 5 and nq > 5.)
Solution:
Download APP for more features
1. Tons of answers.
2. Smarter Al tools enhance your learning journey.
IOS
Download
Download
Android
Download
Download
Google Play
Download
Download