A large airline company called Fusion Fly monitors customer satisfaction by asking customers to rate their experience as a 1, 2, 3, 4, or 5, where a rating of means "very poor" and 5 means "very good". The customers' ratings have a population mean of u=3.38, with a population standard deviation of o = 1.76. Suppose that we will take a random sample of n= 8 customers' ratings. Let x represent the sample mean of the 8 customers' ratings. Consider the samplinc distribution of the sample mean x. Complete the following. Do not round any intermediate computations. Write your answers with two decimal places, rounding if needed. (a) Find u- (the mean of the sampling distribution of the sample mean). (b) Find (the standard deviation of the sampling distribution of the sample mean). Anse

Water specimens are taken from water used for cooling as it is being discharged from a power plant into a river. It has been determined that as long as the mean temperature of the discharge is at most 150F, there will be no negative effects on the river's ecosystem. To investigage whether the plant is in compliance with regulations that prohibit a mean discharge water temperature above 150F, researchers will take 50 specimens at randomly selected times and record the temperature of each specimen. The resulting data will be used to test the hypotheses:H0:μ≤150FH0:μ≤150F Ha:μ>150FHa:μ>150F.(a) In the context of this problem, describe Type I and Type II errors.Type I Error:Select an answer  A Type I error is not obtaining convincing evidence that the mean water temperature is greater than 150F when in fact it is greater than 150F.  A Type I error is obtaining convincing evidence that the mean water temperature is greater than 150F when in fact it is at most 150F. Type II…

A psychologist is interested in the conditions that affect the number of dreams per month that people report in which they are alone. In the general population the number of such dreams per month follows a normal curve, with μ = 5 and σ = 4. The psychologist studies 36 individuals and found that their mean number of alone dreams is 8. What is the Z score for this groups mean in the distribution of sample means?

Find the mean and standard error of the mean of the sampling distribution. Then sketch a graph of the sampling distribution.   The prices of photo printers on a website are normally distributed with a mean of ​$238 and a standard deviation of ​$67. Random samples of size 33 are drawn from this population and the mean of each sample is determined.

A hypertension trial is mounted, and 12 participants are randomly assigned to receive either a new medication or a placebo. Each participant takes the assigned medication, and the participants’ SBP is recorded after 6 months on the assigned medication. The data are shown in Table 7–9. Is there a difference in mean SBP between treatments? Run the appropriate test at a = 0.05. Placebo New Medication 134 114 143 117 148 121 142 124 150 122 160 128

In college, talented runners may join a cross-country team. Runners tend to run their best times when they run even splits. Even splits occur when the runners maintain an even pace throughout the race. The cross-country coach wants to estimate the typical variability in his best runner's 1-mile splits. He takes a random sample of 25 of this runner's mile splits and finds that this runner's mean 1-mile split is 5.44 minutes per mile, with a standard deviation of 0.14 minutes per mile. This runner's 1-mile splits follow a normal distribution. (a) Find the chi-square critical values XL² and Xu² to be used in constructing a 95% confidence interval for the true population standard deviation. (Round your answers to two decimal places.) XL²= XU²= (b) Find the 95% confidence interval for the true variability in his best runner's 1-mile splits. (Round your answers to three decimal places.) lower bound and the upper bound

If we meet these conditions, the sampling distribution of the mean will have a normal shape and ... The mean of the sampling distribution will be u, (i.e., the same as the population mean) and the standard deviation of the sampling distribution will be (that's the population standard deviation divided by the square root of the sample size). In the AP Stats Guy video, he talks about the number of text messages his students send during class. Suppose the average number of text messages his students send during class is u = 30 text messages. If we take samples of say, n = 36 students at a time, we would expect the mean of the sampling distribution we create to be the same as the population mean, 30 text messages. If we can further say that standard deviation of the number of text messages is 12 text messages, by how much would we expect the sample means to vary? (hint, use the formula above) text messages