An analyst at a state's environmental quality commission has just finished processing salt concentration tests on 60 wells in Washington County to represent the more than 1,000 wells across the state. Water with salinity concentration less than 0.05% is considered fresh. The analyst decides to run a one-sample t test at a significance level of a = 0.03 on this sample of wells to determine if the overall salt concentration of the state's water supply exceeds 0.05%. The shape of the sample data is approximately symmetric with no outliers, and its statistics are x = 0.048% Sx = 0.0366% P-value = 0.0166 where x is the sample mean, sz is the sample standard deviation, and the P-value is the probability that results from the t test. The analyst decides that there is enough evidence to conclude that the mean water salinity level exceeds 0.05%. Is this decision valid? To answer this question, complete the following sentence. The conclusion is because

​Cadmium, a heavy​ metal, is toxic to animals.​ Mushrooms, however, are able to absorb and accumulate cadmium at high concentrations. A government set a safety limit for cadmium in dry vegetables at 0.5 parts per million​ (ppm). The cadmium levels in a random sample of one species of edible mushroom are in the accompanying data set. At the 10​% significance​ level, do the data provide sufficient evidence to conclude that the mean cadmium level in this species of mushroom is greater than the​ government's recommended limit of 0.5ppm? Assume that the population standard deviation of cadmium levels in this species of mushroom is 0.45 ppm. Preliminary data analyses indicate that applying the​ z-test is reasonable.​ (Note: The sum of the data is 6.57 ppm.) 0.32 0.44 0.17 0.23 0.79 1.21 0.84 0.24 0.46 0.41 0.92 0.54 State the hypotheses for the​ one-mean z-test.H0​: μ (≠, >, <, =) ________ppmHa​: μ (≠, >, <, =) _________ppmCompute the value of the test…

Four brands of lightbulbs are being considered for use in the final assembly area of the Ford F-150 truck plant in Dearborn, Michigan. The director of purchasing asked for samples of 100 from each manufacturer. The numbers of acceptable and unacceptable bulbs from each manufacturer are shown below. At the .05 significance level, is there a difference in the quality of the bulbs? (Round your answers to 3 decimal places.)   H0: There is no relationship between quality and manufacturer.   H1: There is a relationship.     1. Reject H0 if X2 >____      2. X2 = ____   (Reject or Do Not Reject) H0. Ther (is a/is no) relationship between quality and manufacturer.

Samples were collected from two ponds in the Bahamas to compare salinity values (in parts per thousand). Several samples were drawn at each site. Pond 1: 37.03, 37.45, 36.75, 37.54, 37.71, 37.02, 37.32 Pond 2: 38.89, 39.05, 38.51, 38.53, 38.71 Use a 2% significance level to test the claim that the two ponds have the same mean salinity value. Assume that nothing is known about the population distribution of salinities. (a) Enter the rank values in the same order as in the original sample. The rank values for Pond 1 are:   The rank values for Pond 2 are:   (b) The test statistic is:  . (c) The test critical value is:  . (d) The conclusion isA. There is not sufficient evidence to indicate that the two ponds have different distributions of salinity values.B. There is sufficient evidence to indicate that the two ponds have different distributions of salinity values.

A manufacturing company glues one part to another part during the assembly of its final product. Either too much or too little glue presents a problem. It is important for the pressure of the glue nozzle (pounds per square inch) to be set correctly because it affects the amount of glue (ounces) that is applied. Ten applications are sampled and the following information collected: SSXX  = 129.6            SSYY = 2.345             SSXY = 16.6   X bar = 25.2     Y bar = 2.05 What is the estimated y intercept?

The recommended hours of sleep per night for adults is 8 hours. A doctor, who works at a sleep study facility, believes average number of hours of sleep per night for adults is more than the recommended 8 hours. To test this claim, at th significance level, the doctor collects the following data on a sample of 25 adults at the sleep study facility and records amount of sleep. The following is the data from this study: Sample size = 25 adults Sample mean = 8.5 hours Sample standard deviation = 0.9 hours Identify the null and alternative hypothesis for this study by filling in the blanks with the correct symbol (=#, t represent the correct hypothesis.) Provide your answer below: