Summarize Argument
The meteorologist concludes that his station’s weather predictions are better than its competitors. This is because the majority of times they predicted rain, it rained. The station’s competitors have not been accurate most of the time.
Notable Assumptions
The meteorologist assumes that prediction accuracy is an effective indicator of usefulness and reliability. For example, it could be that the meteorologist's station has only predicted it would rain three times in a given year and it rained two out of those three times, while the competitors predicted it would rain 100 times and it rained 49 out of those 100 times. While the meteorologist’s station may be more accurate, it is not more useful or reliable. The author also assumes a conclusion about weather forecasts broadly using facts about rain—maybe people also care about whether it will snow.
A
The meteorologist’s station forecast rain more often than did the most popular news station in the area.
This strengthens the argument by addressing a potential weakness. It provides additional information that reinforces the meteorologist's assumption that the proportions he compares are comparable, as his station is more accurate even with a larger number of predictions.
B
The less popular of the competing stations does not employ any full-time meteorologists.
This does not affect the argument. How many meteorologists a station employs and their status of employment (i.e., whether they’re full-time, part-time, etc.) does not provide us with information about how reliable or useful their station is in predicting the weather.
C
The most popular news station in the area is popular because of its investigative news reports.
This does not affect the argument. A station being able to put on a good investigative news report doesn’t tell us anything about its weather prediction abilities.
D
The meteorologist’s station has a policy of not making weather forecasts more than three days in advance.
This does not affect the argument. We don’t know if this policy affects the station’s accuracy, and we have no reason to believe that all its competitors don’t share this policy.
E
On most of the occasions when the meteorologist’s station forecast that it would not rain, at least one of its competitors also forecast that it would not rain.
This does not affect the argument. It could be that on all the days the station predicted it would not rain its competitors predicted the same—but still, the station has a higher accuracy of predicting rain on the days it rained. This doesn’t change anything for the argument.