Statistics 3 questions complete solutions correct answers key

Statistics 3 questions complete solutions correct answers key

1.) 

 Flip a coin 60 times. Record the outcome of each of the 60 flips in order from 1 to 60, using the Tally Sheet accompanying the Final Exam. Tally the number of heads and the number of tails and calculate the proportion of heads in your sample.

Based on your sample result, calculate a 95% Confidence Interval for the true population value. Calculate a 95% Confidence Interval for the proportion of heads.

2.)  

Explain the difference between the information given by the tests of statistical significance t and Chi Square, and measures of association Cramer’s V, Gamma and Pearson’s correlation coefficient, r.

Can a test of significance show a statistically significant relationship while a measure of association shows a weak relationship between the variables?

If yes, present an example illustrating how such a situation might occur.

3.)  

A researcher conducts a study of white and black attitudes toward the police in her community.

The percentage of a random sample of white respondents (N = 300) who say they have a favorable attitude toward the police is 55%. The percentage of a random sample of black respondents (N = 250) who say they have a favorable attitude toward the police is 41%.

You are asked if there is a real difference between the percentage of whites and blacks who have a positive attitude toward the police in the larger population, or is this sample difference likely to have occurred by random chance or sampling error.

How do you respond? Explain your answer.

Construct a 95% confidence interval for the proportion of Whites in the population who have a favorable attitude toward the police.