Aboat traveled 252 miles downstream and back. the trip downstream took 12 hours. the trip back took 84 hours. what is the speed of the boat in still water? what is the speed of the current?

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.

Question 10 of 211 pointuse the elimination method to solve the system of equations. choose thecorrect ordered pair.10x +2y = 643x - 4y = -36a. (4,12)b. (-3, 11)c. (2,10)d. (-5, 8)

Acell phone company offers two plans to its subscribers. at the time new subscribers sign up, they are asked to provide some demographic information. the mean yearly income for a sample of 40 subscribers to plan a is $45,000 with a standard deviation of $9,200. for a sample of 25 subscribers to plan b, the mean income is $64,300 with a standard deviation of $7,100. at the 0.025 significance level, is it reasonable to conclude the mean income of those selecting plan b is larger? assume unequal population standard deviations. hint: for the calculations, assume the plan a as the first sample. what is the decision rule? (negative amount should be indicated by a minus sign. round your answer to 3 decimal places.) compute the value of the test statistic. (negative amount should be indicated by a minus sign. round your answer to 2 decimal places.) what is your decision regarding h0 ? reject h0 fail to reject h0 compute the p-value. less than 0.01 between 0.01 and 0.025 between 0.025 and 0.05 between 0.05 and 0.10 greater than 0.10