Here are six more practice guesstimates.
How many men's suits were sold in the United States last year?
Determine:
1. Estimate the population of the United States.
2. Cut that in half to get the number of men.
3. Determine how many men are employed in occupations which require business attire.
4. Determine how many suits the average business attire employee would have purchased (due to weather, fashion changes, cleanings, wear, etc.).
5. Assume (or ask) a number of suits that those men not employed in business attire jobs purchased for religious, social, or other reasons.
6. Sum up the number and present your answer.
To summarize:
Population of the United States: 270 million (or 300 million, to round up).
Half are men - 150 million.
Let's say two-thirds are employed,
150 million x 2/3 = 100 million
Assume every employed man owns one suit = 100 million suits.
Estimate that about a quarter of men are in a field where they must own more than one suit.
If each of those men has an additional two suits, 25 million men x 2 additional suits = 50 million suits, 150 million suits in the United States.
How often does the average suit-owner replace a suit? Perhaps once every three years.
There are 50 million suits sold every year in the United States.
How many tennis balls fit in a swimming pool?
Determine:
1. What is the shape and depth of the swimming pool?
2. What is the volume of a tennis ball?
3. Estimate the volume of the swimming pool based on the depth, length, and width of the pool.
4. Calculate the number of balls by dividing the volume of the pool by the volume of the tennis ball.
5. You may wish to subtract balls due to steps in the pool and the gradual upslope of the pool due to the varying depth (but ask first).
How many windows are there on one of the Twin Towers?
Determine:
1. How many floors does the building have?
2. How many windows are on one face of the building?
3. Multiply the number of windows per face by four and then by the number of floors.
How many gas stations are there in Los Angeles?
Determine:
1. What is the population of Los Angeles?
2. What is the number of cars in Los Angeles? What is the average number of cars per person (including commuters)?
3. How many gas stations are needed per car?
What is the annual size of the golf ball market in the United States? What factors drive demand?
Determine:
1. What is the population of U.S.?
2. What percentage of the population golfs?
3. How often does the average golfer golf?
4. What is the number of balls used in an average golf game (and number that are lost)?
What factors drive demand?
- How many golf courses are being built in the United States?
- How many are planned?
- Is the population of golfers (due to Tiger Woods and his ilk) expanding?
Estimate the total revenues of Disney's Tarzan.M
Here's where some prior knowledge comes in handy.
Determine:
1. What were movie ticket revenues in the United States for Tarzan?
2. What percentage of worldwide sales is the U.S. revenue?
3. How much does Disney make from video sales?
4. What are Disney's revenues from cross licensing agreements (dolls, posters, etc.)?