Statistics - Normal Probability Projects

Chapter 6 46. Thirty percent of the population in a southwestern community are Spanish-speaking Americans.

Chapter 6

46. Thirty percent of the population in a southwestern community are Spanish-speaking Americans. A Spanish-speaking person is accused of killing a non-Spanish-speaking American. Of the first 12 potential jurors, only 2 are Spanish-speaking Americans, and 10 are not. The defendant’s lawyer challenges the jury selection, claiming bias against her client. The government lawyer disagrees, saying that the probability of this particular jury composition is common. What do you think?

Chapter 7

54. Jon Molnar will graduate from Carolina Forest High School this year. He took the American College Test (ACT) for college admission and received a score of 30. The high school principal informed him that only 2 percent of the students taking the exam receive a higher score. The mean score for all students taking the exam is 18.3. Jon’s friends Karrie and George also took the test but were not given any information by the principal other than their scores. Karrie scored 25 and George 18. On the basis of this information, what were Karrie’s and George’s percentile ranks? Assume that the distribution of scores follows the normal distribution.

Chapter 9

48. In a poll to estimate presidential popularity, each person in a random sample of 1,000 voters was asked to agree with one of the following statements:

The President is doing a good job.
The President is doing a poor job.
I have no opinion.

A total of 560 respondents selected the first statement, indicating they thought the President was doing a good job.

Construct a 95 percent confidence interval for the proportion of respondents who feel the President is doing a good job.
Based on your interval in part (a), is it reasonable to conclude that a majority (more than half) of the population believes the President is doing a good job?

Newspaper circulation data analysis (5 points):

Listed below is the average daily circulation for the 50 U. S. newspapers with the largest circulation.