A wholesale dealer of stationery products plots the scatter diagram of his income through the years 1985 to 2000. In which year was his income the highest?

To determine in which year the wholesale dealer's income was the highest, we would need to look at the scatter diagram of his income from 1985 to 2000. The point on the scatter diagram that corresponds to the highest income would indicate the year in which his income was the highest.

Without the actual scatter diagram data, it is not possible to determine the exact year in which his income was the highest. The wholesale dealer would need to analyze the scatter diagram and identify the point with the highest income value to determine the specific year.

The provided context does not mention any specific years or income values, so I cannot answer the question.