Rick's spaceship flies through air at 900 mph if there's no wind. On a trip through the atmosphere from Seattle to Washington DC and back again, he has to deal with the jet stream. He can travel 206 miles there in the same amount of time as it takes to go 154 miles on the way back. How fast is the jet stream?
(treat the spaceship like a boat, it's speed like a boat's speed, and the jet stream is like a current...)
Make sure your answer makes sense, and that Rick can overcome the speed of the jet stream. (4 points)

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