Construct a 98% confidence interval for the population mean, u. Assume the population has a normal distribution. A sample of 15 randomly selected students has a grade point average of 2.71 with a standard deviation of 0.90. O(2.82, 3.82) o (2.12, 4.52) o (2.10, 3.32) o (3.22, 3.42)

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​:…

A hospital administrator believes that the standard deviation of the number of people using outpatient survey per day is greater than 8. A random sample of 15 days is selected. The data are shown below. At α = 0.1, is there enough evidence to support the administrator’s claim? Show your work and indicate the conclusion and assume that the variable is normally distributed.25, 30, 5, 15, 18, 42, 16, 9, 10, 12, 12, 38, 8, 14, 27.

From a sample with n = 32, the mean duration of a geyser's eruptions is 3.42 minutes and the standard deviation is 1.12 minutes. Using Chebychev's Theorem, determine at least how many of the eruptions lasted between 1.18 and 5.66 minutes. At least of the eruptions lasted between 1.18 and 5.66 minutes. (Simplify your answer.)

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…

Assume all populations are normally distributed. A travel analyst claims that the mean price of a round trip flight from New York City to Los Angeles is less than $507. In a random sample of 55 round trip flights from NYC to LA, the mean price is $502. Assume the population standard deviation is $111. At α = 0.05, is there enough evidence to support the travel analyst’s claim?

his question refers to excavations at a national monument. One question the archaeologists asked was: Is raw material used by prehistoric Indians for stone tool manufacture independent of the archaeological excavation site? Two different excavation sites gave the information in the following table. Use a chi-square test with 5% level of significance to test the claim that raw material used for construction of stone tools and excavation site are independent.   Excavation Site   Material Site A Site B Row Total Basalt 756 559 1315 Obsidian 92 103 195 Pedernal chert 514 521 1035 Other 88 91 179 Column Total 1450 1274 2724 (a) What is the level of significance?   (b) Find the value of the chi-square statistic for the sample. (Round the expected frequencies to at least three decimal places. Round the test statistic to three decimal places.)

A manufacturer makes ball bearings that are supposed to have a mean weight of 30 g. A retailer suspects that the mean weight is actually less than 30 g. The mean weight for a random sample of 16 ball bearings is 28.6 g with a standard deviation of 4.4 g. Assume the population standard deviation is not known. How many populations? O2 01 What is the parameter? O Proportion О Мean O Variance O tandard Deviation O Difference between Means