Question

1. A student is considering publishing a new magazine aimed directly at owners of Japanese automobiles. He wanted to estimate the fraction of cars in the United States that are made in Japan. The computer output below summarizes the results of a random sample of 50 autos.  

z-interval for proportion

With 90.00% confidence

0.29938661 < p(japan) < 0.46984416

1. Interpret the computer output.

2. Explain what “90% confidence” means.

3. A politician urging consumers to purchase products manufactured in the United States says, “Half of all cars in the United States are made in Japan.” Does your confidence interval support or contradict this statement? Explain.

Answer 1

Since , the 90% confidence interval for the proportion is 0.29938661 < p(japan) < 0.46984416

Now , we want to test the claim that the half of all cars in the United States made in Japan.

Therefore , the hypothesis is ,

Hypothesis : VS  

Decision : Here , the value 0.5 does not lies in the given 90% confidence interval.

Therefore , reject Ho.

Conclusion : Hence , there is not sufficient evidence to support the claim that the half of all cars in the United States made in Japan.

Therefore , the onfidence interval contradict this statement.