In a recent year, some professional baseball players complained that umpires were calling more strikes than the average rate of 61% called the previous year. At one point in the season, umpire Dan Morrison called strikes in 2231 of 3581 pitches. Use a 0.05 significance level to test the claim that his strike rate is greater than 61%.

The percent of the population that is left-handed has historically been 10%. In a random sample of n=500 people there are 58 that are left-handed. The researcher would like to test the hypothesis that the percent of the population that is left-handed has increased. Determine the value of the test statistic

It is bleieved that the percent of convicted felons who have a history of juvenile deliquency is 70%.  Is there evidence to support the claim that the actual percentage is more than 70% if out of 200 convicted felons, we find that 154 have a history of juvenile deliquency?  Set the level of significance at a = 0.05

In a city with three high schools, all the ninth graders took a Standardized Test, with these results: High School Mean score on test Number of ninth graders Glenwood 76 272 Central City 93 325 Lincoln High 73 180 The city's PR manager, who never took statistics, claimed the mean score of all ninth graders in the city was 80.7 . Of course, that is incorrect. What is the mean score for all ninth graders in the city? Round to one decimal place.mean of all ninth grader's scores =