Hypothesis Testing- Practice Questions
Q: 1 A local school board member wants to know if sophomore students at Lincoln High School have approximately the same reading level as the state average for tenth graders. The state average is 150 words per minute with a standard deviation of 15. The level of the test is to be set at .05. A random sample size of 100 tenth graders has been drawn, and the resulting average is 157 words per minute.
Q: 2 A can of peeled whole tomatoes is supposed to contain an average of 19 ounces of tomatoes (excluding juice). The actual weight is normally distributed random variable whose standard deviation is known to be 1.9 ounces. A random sample of 25 cans yield 18 ounces as the average weight. At 1% level of significance, test the hypothesis that the mean weight is below 19 ounces.
Q: 3 A U.S. dime is supposed to weight 2.268 grams with a SD of 0.026 grams. A random sample of 15 circulated dimes showed a mean weight of 2.256 grams. Test the hypothesis, under the assumption that data is normally distributed, the mean weight of all the circulated dimes lower than the specification.
Q: 4 A company currently pays its production employees a mean wage of $15.00 per hour with a standard deviation of $2.40. The company is planning to build a new factory and is considering several locations. The availability of labor at a rate less than $15.00 per hour is a major factor in the location decision. For one location, a sample of 40 workers showed a current mean hourly wage of $14.00. At 10% level of significance, do the sample data indicate that the location has a mean wage rate significantly below the $15.00 per hour rate?
Q: 5 From long experience with a process for manufacturing an alcoholic beverage it is known that the yield is normally distributed with a mean of 500 and a standard deviation of 96 units. For a modified process the yield is