Lake Martin and Lake Fields are two large local lakes inhabited by white sturgeon. A while back there was an environmental disaster at Lake Martin. Melissa is an ecologist who wants to see if the mean weight (in kg) of adult white sturgeon now living in Lake Martin is less than the mean weight (in kg) of adult white sturgeon now living in Lake Fields. The ecologist catches a random sample of 11 adult white sturgeon at Lake Martin and a random sample of 12 adult white sturgeon at Lake Fields. (These samples are chosen independently.) Each fish has its weight (in kg) recorded. The white sturgeon caught at Lake Martin have a sample mean weight of 90.76 with a sample variance of 20.69. The white sturgeon caught at Lake Fields have a sample mean weight of 99.85 with a sample variance of 172.60. Assume that the two populations of weights are approximately normally distributed. Can the ecologist conclude, at the 0.10 level of significance, that the population mean of the weights of adult white sturgeon now living in Lake Martin is less than the population mean of the weights of adult white sturgeon now living in Lake Fields? Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places. (If necessary, consult a list of formulas.) (a) State the null hypothesis Ho and the alternate hypothesis H₁. H₁ :☐ μ σ р x S <0 (b) Determine the type of test statistic to use. (Choose one) (c) Find the value of the test statistic. (Round to three or more decimal places.) (d) Find the critical value. (Round to three or more decimal places.) (e) At the 0.10 level of significance, can the ecologist conclude that the mean weight of adult white sturgeon now living in Lake Martin is less than the mean weight of adult white sturgeon now living in Lake Fields? O Yes O No □≠口 □□ □<ロ ㅁㅁ □□ □<ロ

In the US, 45.1% of all people have type O blood, 39.6% have type A blood, 10.9% have type B blood and 4.4% have type AB blood. A researcher wants to see if the distribution of blood type is different for millionaires. The table below shows the results of a random sample of 614 millionaires. What can be concluded at the significant level of a = 0.05. For this study, we should use Chi-Square test for Goodness of Fit Your friend Caroline helped you with the null and alternative hypotheses... Ho : The distributions of blood types are the same between the general population and the millionaires. Ha: The distributions of blood types are NOT the same between the general population and the millionaires. You drew 614 samples, and the observed frequencies are recorded below. Please complete the table (round answers to at least 4 decimal places). Blood Type 0 A B AB Observed Count 274 230 57 53 Expected Count Click Download CSV to download csv file of data or copy/paste the data into Excel.…

A nationwide job recruiting firm wants to compare the annual incomes for childcare workers in Illinois and Massachusetts. Due to recent trends in the childcare industry, the firm suspects that the that the mean annual income of childcare workers in the state of Illinois is greater than the mean annual income of childcare workers in Massachusetts. To see if this is true, the firm selected random sample of 25 childcare workers from Illinois and an independent random sample of 25 childcare workers from Massachusetts and asked them to report their mean annual income. The data obtained were as follows. Annual income in dollars 45679, 47412, 38478, 44646, 44364, 45265, 41423, 45861, 45936, 34016, 43020, 4960o8, 43710, 45738, 41546, 38681, 34889, 39468, 45463, 53593, 40847, 38255, 45708, 57662, 54356 Illinois 41743, 36349, 44588, 40341, 32544, 38226, 46463, 42255, 38621, 32502, 37378, 40215, 41155, 38509, 47586, 46910, 56502, Massachusetts 48907, 41861, 51211, 55186, 39078, 48263, 48059,…

Two popular brands of tires for tractor-trailers are the Puma and the Eternal. Salma is a buyer for a major shipping company and wants to determine if there is any difference between the two brands of tire in the mean distance (in thousands of km) driven on them before they need to be replaced. In the company's testing lab, Salma tests a random sample of 14 Puma tires and a random sample of 15 Eternal tires. (These samples are chosen independently.) For the Puma tires, the sample mean distance (in thousands of km) until they would need to be replaced is 54.71 with a sample variance of 5.95. For the Eternal tires, the sample mean distance (in km) until they would need to be replaced is 50.21 with a sample variance of 37.75. Assume that the two populations of distances driven are approximately normally distributed. Can Salma conclude, at the 0.05 level of significance, that there is a difference between the population mean of the distances (in thousands of km) driven on Puma tires before…