Question

(Note: a research study on coniferous trees of the American West
may sound really boring, but sometimes you might get to climb one
Scientists studying beetle infections on in Western forests discover
that in one particular region called Doug's Backyard, the number of
trees with beetle infestations seems lower than the surrounding
area. In the entire forest they're studying, the rate of severe beetle
infestations is about 0.07 (7%) of the trees, but in a sample of trees
from Doug's Backyard, they found just 0.035 (3.5%) of the trees to
be infested. Based on their statistical calculations, the likelihood that
their sample is just an accident -- that is, that the trees from Doug's
Backyard are actually infested at the same rate as the whole region -
- is 0.003, so they deem their results significant
In this story problem:
• p = 0.07
• Ô
[Select)
• Po =
[ Select)
• The p-value
[Select]

Answer 1

Answer:

p = 0.07

p-hat = 0.035

p0 = 0.07

p-value = 0.003

Step-by-step explanation:

p = population parameter, in this case, the rate of infestations across all trees in the forest

p-hat = test statistic, in this case, the rate of infestations found in the sample of trees, i.e. those in Doug's backyard

p0 = the null hypothesis, in this case, the rate of infestations within the forest is correctly evaluated at 0.07 or 7%

p-value = the likelihood any difference between p and p-hat is down to chance

In this case 0.003 as the p-value means there is only 0.3% probability of our statistic value of 0.035 being down to variability and chance meaning it is 99.7% likely that there is some reason behind this difference;

We would accept the alternative hypothesis which says the current parameter value, 0.07, is in fact incorrect (either too high or too low, in this case, likely too high).