Diabetes and Pollution

Diabetes tends to be more prevalent in urban populations but why this is so not fully understood. A recent study on mice was designed to investigate the link between diabetes and air pollution, The study involved 28 mice with 14 randomly selected to have filtered air pumped into their cage while the other 14 breathed particulate matter that simulated common air pollution. The response variable is the amount of insulin resistance each mouse had after 24 weeks, higher insulin resistance indicates a greater risk for developing diabetes.

1. Is this an observational study or randomized experiment

Randomized experiment

Observational study

(B) If we are interested in whether there is a difference in mean insulin resistance between the two groups, what are the null and alternative hypotheses?

Let the filtered air group 1 and the polluted air group be group 2

The difference in sample means from the original sample is D = x1-x2=1.8-6.2=-4.4 The figure below shows 1000random assignments of insulin resistant scores from the original sample to each of the two groups. Is it likely we will reject the null hypothesis?

What is the p-value

Round your answer to one decimal place

p-value =

(e) State the conclusion of the test in context

There is mild evidence that air pollution has no effect on insulin resistance

There is strong evidence that air pollution has no effects on insulin resistance

There is strong evidence that air pollution does affect insulin resistance

There is mild evidence that air pollution does affect insulin resistance

Reject Ho

Do not reject Ho