Chapter 7.4 Extra Practice

Name: ______

Chapter 7.4 – Extra Practice

1.) In a Harris poll, adults were asked if they are in favor of abolishing the penny. Among the responses, 1261 answered “no,” 491 answered “yes,” and 384 had no opinion. Carry out an inference to show whether this sample is enough evidence to show the proportion of people who are in favor of abolishing the penny is less than 25%.

2.) A recent study showed that 53% of college applications were submitted online (based on data from the National Association of College Admissions Counseling). Assume that this result is based on a simple random sample of 1000 college applications, with 530 submitted online. Use a 0.01 significance level to test the claim that the majority of college applications are submitted online.

3.) In a survey, 1864 out of 2246 randomly selected adults in the United States said that texting while driving should be illegal (based on data from Zogby International). Carry out an inference to test the claim that 80% of adults believe that texting while driving should be illegal.

4.) Refer to the data set of M&Ms and find the sample proportion of red M&Ms. Use that result to test the claim of Mars, Inc., that 20% of its plain M&Ms candies are red.

5.) According to Information Please almanac, the percentage of movies with ratings of R has been 55% during the last 33 years. Refer to the data set on movies and find the proportion of movies with ratings of R. Use a 0.01 significance level to test the claim that the movies in the data set from a population in which 55% of the movies have R ratings.