(a) Find the sample mean. x = 4263.1 (Round to one decimal place as needed.) (b) Find the sample standard deviation. s = 260.1 (Round to one decimal place as needed.) (c) Construct a 95% confidence interval for the population mean μ. A 95% confidence interval for the population mean is (). (Round to one decimal place as needed.) ...

A population has a standard deviation ? of 25 units. (Give your answers correct to two decimal places.) (a) Find the standard error for the mean if n = 30.(b) Find the standard error for the mean if n = 46.(c) Find the standard error for the mean if n = 71.

The output below is for a t-test for the hypothesis: Individuals living in bad neighborhoods commit more crime than those living in good neighborhoods. The data in the Group Statistics section provides you with the average number of crimes committed by individuals living in good and bad neighborhoods and the standard deviation of this same variable. The findings of significance are located in the Independent Samples Test section. Pay particular attention to the "t" column and the "Sig (2-tailed)"column. The "t" column is the t value that you would have calculated by hand (as we learned in class). The "Sig (2-tailed)"column provides you with the p value (the level of significance of this relationship). In this column, any value below .05 indicates that you would have rejected your null hypothesis. 1. Can someone tell me about the relationship of all these data? I'm trying to determine if my hypothesis, listed below, can be proven or disproven? 2. What is the independent variable and…

A random sample of 15 exam scores showed a standard deviation of 6.0 points. Find the 95 percent confidence interval for the population standard deviation. Use Appendix E to obtain the values of  χ2LχL2 and χ2UχU2 . (Round your answers to 2 decimal places.) The 95% confidence interval is from ______ to __________  .

You want to obtain a sample to estimate a population mean. Based on previous evidence, you believe the population standard deviation is approximately σ=51.3. You would like to be 98% confident that your estimate is within 10 of the true population mean. How large of a sample size is required?

For the following situation, find the mean and standard deviation of the population. List all samples (with replacement) of the given size from that population and find the mean of each. Find the mean and standard deviation of the sampling distribution and compare them with the mean and standard deviation of the population. The scores of three students in a study group on a test are 94, 93, 97. Use a sample size of 3. The mean of the population is (Round to two decimal places as needed.) C

Suppose that Melanie is a researcher who wishes to estimate the mean birthweight of full-term babies in her hospital. What is the minimum number of babies should she sample if she wishes to be at least 90% confident that the mean birthweight of the sample is within 225 grams of the the mean birthweight of all babies? Assume that the distribution of birthweights at her hospital is normal with a standard deviation of 600 g.

Use the following information for questions 3 and 4.  A study of class lengths at two schools was done using independent samples. 31 classes were chosen from each. The first school had a mean length of 50.1 minutes and a standard deviation of 1.6 minutes. The second school had a mean length of 48.9 and a standard deviation of 2.2 minutes. We want to determine at α = 0.01 if the means are different. Assume all test conditions are satisfied. What are the null and alternate hypotheses (write in equation/inequality form)?

A store owner has found that a sample of customers purchased an average of 3.0 pounds of meats with a sample standard deviation of 0.5 lb. If the store's meat scale is off by 0.1 lb (e.g., a purchase listed as 1 lb actually weighs 1.1 lb), what will be the values of the sample mean and standard deviation after the owner corrects his data for the weighing error? Show the formula and work