Use technology to construct the confidence intervals for the population variance σ2 and the population standard deviation σ. Assume the sample is taken from a normally distributed population.   c=0.95​, s=39​, n= 15

esc Introduction A chain of restaurants has historically had a mean wait time of 9 minutes for its customers. Recently, the restaurant added several very popular dishes back to their menu. Due to this, the manager suspects the wait time, μ, has increased. He takes a random sample of 44 customers. The mean wait time for the sample is 9.6 minutes. Assume the population standard deviation for the wait times is known to be 3.3 minutes. Can the manager conclude that the mean wait time is now greater than 9 minutes? Perform a hypothesis test, using the 0.05 level of significance. (a) State the null hypothesis Ho and the alternative hypothesis H₁. Ho: O H₁:0 (b) Perform a Z-test and find the p-value. Here is some information to help you with your Z-test. The value of the test statistic is given by Standard Normal Distribution Step 1: Select one-tailed or two-tailed. O One-tailed O Two-tailed Explanation μ Check □<口 X X OSO 020 0=0 x-H √n • The p-value is the area under the curve to the right…

Find the F-test statistic to test the claim that the population variances are equal. Both distributions are normal. The standard deviation of the first sample is 3.96014.5373 is the standard deviation of the second sample.

Researchers conducted a study to determine whether magnets are effective in treating back pain. Pain was measured using the visual analog​ scale, and the results shown below are among the results obtained in the study. Higher scores correspond to greater pain levels. Assume that the two samples are independent simple random samples selected from normally distributed​ populations, and do not assume that the population standard deviations are equal. Complete parts​ (a) to​ (c) below.   Reduction in Pain Level After Magnet Treatment ​(μ1​): n=29​, x=0.58​, s=0.95 Reduction in Pain Level After Sham Treatment ​(μ2​): n=29​, x=0.48​, s=1.56       Question content area bottom Part 1 a. Use a 0.05 significance level to test the claim that those treated with magnets have a greater mean reduction in pain than those given a sham treatment​ (similar to a​ placebo).   What are the null and alternative​ hypotheses?     A. H0​: μ1≠μ2 H1​: μ1<μ2   B. H0​: μ1<μ2 H1​:…

Use technology to construct the confidence intervals for the population variance σ2 and the population standard deviation σ. Assume the sample is taken from a normally distributed population. c=0.98​, s2=19.36​, n=26 a. The confidence interval for the population variance is   b. The confidence interval for the population standard deviation is

An IQ test is designed so that the mean is 100 and the standard deviation is 10 for the population of normal adults. Find the sample size necessary to estimate the mean IQ score of statistics students such that it can be said with 99% confidence that the sample mean is within 4 IQ points of the true mean. Assume that σ=10 and determine the required sample size using technology. Then determine if this is a reasonable sample size for a real world calculation.

Researchers conducted a study to determine whether magnets are effective in treating back pain. Pain was measured using the visual analog​ scale, and the results shown below are among the results obtained in the study. Higher scores correspond to greater pain levels. Assume that the two samples are independent simple random samples selected from normally distributed​ populations, and do not assume that the population standard deviations are equal. Complete parts​ (a) to​ (c) below.   Reduction in Pain Level After Magnet Treatment ​(μ1​): n=27​, x=0.46​, s=0.89 Reduction in Pain Level After Sham Treatment ​(μ2​): n=27​, x=0.42​, s= 1.43   * Find the t stat * Find the p value * state the conclusion * Does the confidence interval support the conclusion of the test * Does it appear that magnets are effective in treating back​ pain? Is it valid to argue that magnets might appear to be effective if the sample sizes are​ larger? * Is it valid to argue that magnets might appear to be…

Use technology to construct the confidence intervals for the population variance σ2 and the population standard deviation σ. Assume the sample is taken from a normally distributed population.   c=0.99​, s2=19.36​, n= 25

Find the F-test statistic to test the claim that the population variances are equal. Both distributions are normal. The standard deviation of the first sample is 2.44628.0027 is the standard deviation of the second sample.

Cell Phone Lifetimes A recent study of the lifetimes of cell phones found the average is 23.8 months. The standard deviation is 5.8 months. If a company provides its 33 employees with a cell phone, find the probability that the mean lifetime of these phones will be less than 23.8 months. Assume cell phone life is a normally distributed variable, the sample is taken from a large population, and the correction factor can be ignored. Use a TI-83 Plus/TI-84 Plus calculator. Round your answer to at least four decimal places. <PX23.8)=