Add degrees of freedom

Espanol 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. Lisa 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 10 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 D sturgeon caught at Lake Martin have a sample mean weight of 78.78 with a sample variance of 26.58. The white sturgeon caught at Lake Fields have a sample mean weight of 92.88 with a sample variance of 393.58. Assume that the two populations of weights are approximately normally distributed. Can the ecologist conclude, at the 0.05 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. Ho : D S p (b) Determine the type of test statistic to use. (Choose one) V (c) Find the value of the test statistic. (Round to three or more decimal places.) 0 00 X ? (d) Find the p-value. (Round to three or more decimal places.) (e) At the 0.05 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? Yes No