A company claims that a new manufacturing process changes the mean amount of aluminum needed for...
Company ABC claims that they produces cans whose diameters are normally distributed with a population mean of 2 inches and a population standard deviation of 0.06 inch. A customer wants to check if the mean diameter of the cans is different than 2 inches. He takes a random sample of nine samples and finds a sample mean of 1.95 inches. Use a significance level of α = 0.07 to perform a hypothesis test using p value approach. Answer key: Two...
A company claims that the mean volume of the soda in its cans is 12.0 ounces. In a random sample of 8 of its cans, the mean is found to be 12.1 ounces. Based on past research, the population standard deviation is assumed to be 0.1 ounces. Test the claim that the mean is 12.0 ounces. Use a 0.01 level of significance. a) State the null and alternative hypotheses. b) Find the value of the test statistic. Use the appropriate...
the mean price is $2.78. Please 4) A sample of 16 overweight people uses a new reducing pill for 6 weeks and has a mean weight loss of 25 lbs. The standard deviation is 8 lbs. a) Find a 95% confidence interval for the mean weight loss. b) If the same information was found using a sample of 50, how would that affect the length of the confidence interval? 5) A study is taken to see if teacher's salaries are...
A cereal company claims that mean weight of cereal boxes is at most 16.1 ounces. Suppose that a plant manager wishes to test whether the true mean weight of cereal boxes is greater than 16.1 ounces. Suppose that for this problem the population standard deviation is 0.4 and the population distribution is normal. The manager obtain a random sample of size 25 and finds a mean of 16.3 ounces. Using p value approach test the claim of company at significance...
2 Samples of size 5 are selected from a manufacturing process. The mean of the sample ranges is 0.50. What is the estimate of the standard deviation of the population? (Round your answer to 3 decimal places.) 4 points Standard deviation Book Print elences
Crossett Trucking Company claims that the mean weight of its delivery trucks when they are fully loaded is 6,050 pounds and the standard deviation is 320 pounds. Assume that the population follows the normal distribution. Fifty-five trucks are randomly selected and weighed. Within what limits will 99 percent of the sample means occur?
Samples of size 8 are selected from a manufacturing process. The mean of the sample ranges is 0.6. What is the estimate of the standard deviation of the population? (Round your answer to 3 decimal places.)
An industrial company claims that the mean pH level of the water in a nearby river is 6.8. You randomly select 19 water samples and measure the pH of each. The data from the 19 water samples appeared to be unimodal and symmetric and had a mean pH level of 6.7 and a standard deviation of 0.24. Is this evidence that the mean pH level of the water in this river is not 6.8? The null and alternative Hypotheses for...
Statistics Grades: The statistics grades in the fall semester had mean of 65. The SRS were taken from different statistics groups (A, B, C and D) considering that the total number of students that took part on the exam was 110. Assuming that the change in the grades has a normal distribution with standard deviation σ= 10, We computed a 90% confidence interval of the mean change in score μ in the population of all statistics students. A) Find a...
2. In making aluminum castings into alternator housings, an average of 3.5 ounces per casting must be trimmed off and recycled as a raw material at the DAVID remanufacturing plant. A new manufacturing procedure has been proposed to reduce the amount of aluminum that must be recycled in this way. For a sample of 11 castings made with the new process the sample mean is 3.043 and sample standard deviation is 0.507. Using an appropriate hypothesis test, does the new...