In: Statistics and Probability
1.4.26 Researchers wanted to test the hypothesis that living in the country is better for your lungs than living in a city. To eliminate the possible variation due to genetic differences, they located seven pairs of identical twins with one member of each twin living in the country, the other in a city. For each person, they measured the percentage of inhaled tracer particles remaining in the lungs after one hour: the higher the percentage, the less healthy the lungs. They found that for six of the seven twin pairs the one living in the country had healthier lungs.
Is the alternative hypothesis one-sided or two-sided? why?
Based on the sample size and distance between the null value and the observed proportion, estimate the strength of evidence: inconclusive, weak but suggestive, moderately strong, strong, or overwhelming.
Here are probabilities for the number of heads in seven tosses of a fair coin:
# Heads |
0 |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
Probability |
0.0078 |
0.0547 |
0.1641 |
0.2734 |
0.2734 |
0.1641 |
0.0547 |
0.0078 |
Compute the p-value and state your conclusion.