Suppose that a manufacturer of laptop batteries claims that his product last more than 950 hours. They test 45 batteries and found a sample mean of 925 hours and the population standard deviation of 55 hours. Use 5% significance level. Should the claim be accepted?
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Suppose that a manufacturer of laptop batteries claims that his product last more than 950 hours. They test 45 batteries and found a sample
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- A manufacturer claims that a certain brand of cold tablets contains an average 600 mg of acetaminophen. To test this claim, a researcher creates a random sample of 32 tablets. The mean of this sample is 631.7 mg, and the standard deviation is 62.3 mg. Test the claim using a level of significance of 1%. What type of test will be used in this problem? What evidence justifies the use of this test? Check all that apply The original population is approximately normal The population standard deviation is not known The sample standard deviation is not known There are two different samples being compared np>5 and nq>5 The sample size is larger than 30 The population standard deviation is known Enter the null hypothesis for this test.H0 Enter the alternative hypothesis for this test.H1: Is the original claim located in the null or alternative hypothesis? What is the test statistic for the given statistics? What is the p-value for this test? What is the decision…Many cheeses are produced in the shape of a wheel. Because of the differences in consistency between these different types of cheese, the amount of cheese, measured by weight, varies from wheel to wheel. Heidi Cembert wishes to determine whether there is a significant difference, at the 10% level, between the weight per wheel of Gouda and Brie cheese. She randomly samples 18 wheels of Gouda and finds the mean is 1.3 lb with a standard deviation of 0.3 lb; she then randomly samples 10 wheels of Brie and finds a mean of 0.95 lb and a standard deviation of 0.21 lb. What is the df and p-value for Heidi's hypothesis of equality? Assume normality. (Give your answer correct to four decimal places.)A manufacturer claims that a certain brand of cold tablets contains an average 600 mg of acetaminophen. To test this claim, a researcher creates a random sample of 32 tablets. The mean of this sample is 631.7 mg, and the standard deviation is 62.3 mg. Test the claim using a level of significance of 1%. What type of test will be used in this problem? What evidence justifies the use of this test? Check all that apply The original population is approximately normal The population standard deviation is not known The sample standard deviation is not known There are two different samples being compared np>5 and nq>5 The sample size is larger than 30 The population standard deviation is known Enter the null hypothesis for this test.H0 Enter the alternative hypothesis for this test.H1: Is the original claim located in the null or alternative hypothesis? What is the test statistic for the given statistics? What is the p-value for this test? What is the decision…
- 8:48 ← Brase Worksheet 7.2 - Saved ← ...| 9% This document contains ink, shapes an... Instructions: Convert the raw scores in parts (a), (b), and (c) of Problem 11 in the textbook, which is reproduced here. 11. z Scores: Red Blood Cell Count Let x = red blood cell (RBC) count in millions per cubic millimeter of whole blood. For healthy females, x has an approximately normal distribution with mean = 4.8 and standard devia- tion = 0.3 (based on information from Diagnostic Tests with Nursing Implications, edited by S. Loeb, Springhouse Press). Convert each of the following x intervals to z intervals. (a) 4.5 < x (b) x < 4.2 (c) 4.0A new drug is being tested to see if it reduces the frequency of migraines. Study participants were divided into two groups. 49 participants in group 1 received the medication; 42 participants in group 2 received a placebo. After a period of six months, group 1 had a mean of 4 migraines. It is known that the population standard deviation for this group is 1.3 migraines. Group 2 had a mean of 5.4 migraines. The population standard deviation for this group is 1.7 migraines. Can we conclude that the medication reduces the population mean number of migraines? Use αα =0.01. Note: If t-test, then unequal variances are assumed. Question a)Let: μ1μ1 = the population mean number of migraines with the medication μ2μ2 = the population mean number of migraines with the placebo (Step 1) State the null and alternative hypotheses by selecting the appropriate symbol, and identify which tailed test: H0:H0: μ1μ1 μ2μ2 H1:H1: μ1μ1 μ2μ2 Which tailed test…Two brands of batteries are tested, and their voltages are compared. The summary statistics follow. For sample 1, the sample size is 27; the population standard deviation is 0.3 volts and the mean is 9.2 volts. For sample 2, the sample size is 30; the population standard deviation is 0.1 volts and the mean is 8.8 volts. Is the mean of sample 1 smaller than the mean of sample 2? Using a significance level of 0.05. a) Identify the claim and state the hypotheses. b) What is the test statistics? Find the critical values (s). c) Make the decision to reject or not reject the null hypothesis and explain why. d) Graph your decision and include all the values. That is, the mean, the standard deviation, the critical value(s), the rejection region. e) Set up the formula with the correct numbers for the 95% confidence interval of the mean number of jobs.Fran is training for her first marathon, and she wants to know if there is a significant difference between the mean number of miles run each week by group runners and individual runners who are training for marathons. She interviews 42 randomly selected people who train in groups and finds that they run a mean of 47.1 miles per week. Assume that the population standard deviation for group runners is known to be 4.4 miles per week. She also interviews a random sample of 47 people who train on their own and finds that they run a mean of 48.5 miles per week. Assume that the population standard deviation for people who run by themselves is 1.8 miles per week. Test the claim at the 0.01 level of significance. Let group runners training for marathons be Population 1 and let individual runners training for marathons be Population 2. Step 2 of 3 : Compute the value of the test statistic. Round your answer to two decimal places.A pharmaceutical company needs to know if its new cholesterol drug, Praxor, is effective at lowering cholesterol levels. It believes that people who take Praxor will average a greater decrease in cholesterol level than people taking a placebo. After the experiment is complete, the researchers find that the 44 participants in the treatment group lowered their cholesterol levels by a mean of 18.7 points with a standard deviation of 3.3 points. The 39 participants in the control group lowered their cholesterol levels by a mean of 18.1 points with a standard deviation of 2.1 points. Assume that the population variances are not equal and test the company’s claim at the 0.02 level. Let the treatment group be Population 1 and let the control group be Population 2. Step 1 of 3 : State the null and alternative hypotheses for the test. Fill in the blank below. H0: μ1=μ2 Ha : μ1⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯μ2 Step 2 of 3: what is the test statistic Step 3 of 3: draw a conclusion, fail or reject. Is…A pharmaceutical company needs to know if its new cholesterol drug, Praxor, is effective at lowering cholesterol levels. It believes that people who take Praxor will average a greater decrease in cholesterol level than people taking a placebo. After the experiment is complete, the researchers find that the 46 participants in the treatment group lowered their cholesterol levels by a mean of 19.5 points with a standard deviation of 4.9 points. The 37 participants in the control group lowered their cholesterol levels by a mean of 18.4 points with a standard deviation of 4.1 points. Assume that the population variances are not equal and test the company's claim at the 0.02 level. Let the treatment group be Population 1 and let the control group be Population 2. Step 2 of 3: Compute the value of the test statistic. Round your answer to three decimal places.In 16 women with diabetes, the morning blood sugar mean was 49.4 with a standard deviation of 24.0. In normal healthy women, the mean was 47.0. From the sample information, can we conclude that the blood sugar mean in women with rheumatoid arthritis is greater than that in normal women? Assume a significance level of 0.05.The ACCUPLACER is a college readiness exam. The scores for the math section are normally distributed with a mean of 75 and standard deviation of 8. A college policy is that the bottom 15% of test takers are required to take a remedial math course over the summer. Students who score below what score will have to take the summer course?In one city, the average amount of time that tenth-graders spend watching television each week is 23 hours. The principal of Birchwood High School believes it is less for the 10th grade students that at his school. For a sample of 95 tenth-graders from the school, the mean amount of time spent watching television per week was 21.9 hours. Assuming a population standard deviation of 3.1 hours, does the data provide sufficient evidence to conclude that for all tenth-graders at Birchwood High school, the mean amount of time spent watching television per week is less than the city average of 23 hours? Perform the appropriate hypothesis test using a significance level of 0.005. What are the hypotheses? What is the test statistic? Is it a z or a t? Find the P-value for this test statistic. How does it compare to the significance level? On the normal curve, indicate the location of the test statistic and the p-value. (label them on the graph) Write…
