A field researcher is gathering data on the trunk diameters of mature pine and spruce trees in a certain area. The following are the results of his random sampling. Can he conclude, at the 0.10 level of significance, that the average trunk diameter of a pine tree is greater than the average diameter of a spruce tree?
|
Pine trees |
Spruce trees |
| Sample size |
20 |
30 |
| Mean trunk diameter (cm) |
45 |
39 |
| Sample variance |
100 |
150 |
What is the test value for this hypothesis test?