A recent study of business travelers claims they spend an average of $41.00 per day on meals. As a test of this claim, a random sampling of 16 business travelers found they had spent an average of $45.00 per day with a standard deviation of $3.65. What are the critical values for a two-tailed t test of this claim with α = 0.05

A college entrance exam company determined that a score of 24 on the mathematics portion of the exam suggests that a student is ready for college-level mathematics. To achieve this goal, the company recommends that students take a core curriculum of math courses in high school. Suppose a random sample of 250 students who completed this core set of courses results in a mean math score of 24.4 on the college entrance exam with a standard deviation of 3.1. Do these results suggest that students who complete the core curriculum are ready for college-level mathematics? That is, are they scoring above 24 on the mathematics portion of the exam? Complete parts a) through d) below. *** b) Verify that the requirements to perform the test using the t-distribution are satisfied. Check all that apply. A. The sample size is larger than 30. B. The students were randomly sampled. C. A boxplot of the sample data shows no outliers. D. The students' test scores were independent of one another. E. The…

A national online business magazine reports that the average cost of a speeding ticket in Miami, including court fees, is $220. A local police department claims that this amount has increased. To test their claim, they collect data from a simple random sample of 16 drivers who have been fined for speeding in the last year. Assuming that the distribution of speeding ticket costs is normally distributed and the population standard deviation is $13, is there sufficient evidence to support the police department’s claim at the 0.02 level of significance?

An avionics company uses a new production method to manufacture aircraft altimeters. A single random sample of new altimeters resulted in the errors listed below. Use a 5% significance level to test the claim that the new production method has errors with a standard deviation greater than 32.2 ft, which was the standard deviation for the old production model (o). If it appears that the standard deviation is greater, does the new production method appear to be better or worse than the old method? Should the company take any action? -42 78 -22 -72 -45 15 17 51 -5 -53 -9 -109 Find the upper and lower boundaries of the 95% confidence interval for o. 98 37 32 73 89