To determine which location has the highest average in the LDS, which steps are appropriate?

• A. Subset by location, compute means for each, and compare the results.
• B. Compute the overall average across all locations.
• C. Ignore missing data and take the first location.
• D. Use the month as a factor only.

Answer: (A)

When you want to know which location has the highest average, you must compare averages across separate groups. That means splitting the data by location, calculating the mean for each location, and then comparing those means to see which is the largest. Subsetting by location and computing a mean for each group keeps the differences between locations visible, so you can identify the top one.

Computing a single overall average across all locations hides those differences, because it blends all data into one number and you lose information about which location contributed to the higher or lower values.

Taking data with missing values as if they don’t matter and just using the first location is arbitrary and biased. Merely treating the month as a factor doesn’t directly answer which location has the highest average; it might help adjust for monthly effects, but you’d still need location-specific means or a model that estimates location effects to determine the top location.

So, the right approach is to group by location, compute the mean within each location, and then compare those means to identify the highest.