This study investigates a number of problems for people adjusting to high altitude. A cohort of 17 people were measured at sea level then again at high altitude in the Himalayas over the following two weeks of living at high altitude (5050m). All in the cohort were measured at Day 1-3 and 12 of the people were measured at Days 7-9 and again at Days 12-15.

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### Tasks

The data for this study is in the file brain blood flow.xls**Task 1:**Carry out a test on the 17 people to establish if there is a difference between the measures at sea level and the measures after days 1-3 at high altitude. Set up the 95% confidence interval for the difference between the means. Why is this test a dependent samples test and why is this test better than the unpaired test for comparing means?**Task 2:**Compare the sea level (baseline) values with the 12 readings at Day 7-9 and Days 12-15. (At University you will see how to compare the four samples simultaneously by using a procedure for dealing with longitudinal data).**Task 3:**Investigate the scatter diagram for the variables in the file.