Use the t-distribution to find a confidence interval for a difference in means μ1-μ2 given the relevant sample results. Give the best estimate for #1-μ2, the margin of error, and the confidence interval. Assume the results come from random samples from populations that are approximately normally distributed A 90% confidence interval for μ 1-12 using the sample results-,-78.3, si-11 .7, ni = 35 and x2 = 64.4, s2-7.8, n2 = 20 Enter the exact answer for the best estimate and round your answers for the margin of error and the confidence interval to two decimal places. Best estimate =
Margin of error Confidence interval:

Two times a number plus three times another number equals 4. three times the first number plus four times the other number is 7. find the numbers

At the beginning of a call to the cable company, a message tells customers, "after you finish talking to our customer service representative, you will be asked to take a five-question survey about the level of service you recieved. it would be appreciated if you could stay on the line to answer the survey questions." what type of sampling is the cable company using?

Runners run around the school's football field. the cross country coach determines that the width of the field is seventy yards shorter than the length. part a write an expression that represents the perimeter of the football field. let x represent the length of the football field. include parentheses in your expression. next, write an equivalent expression that does not include parentheses. what property or properties did you use to simplify? explain. part b the cross country coach later determines that the length of the football field is 120 yards. all students must run five laps. using your answer from part a, determine the actual number of yards that each athlete must run in the tryouts. in order to make the team, students must complete the laps in 6 minutes. how quickly must they run each lap?