Home / 21,321.40-31,982.10-11,990.20

Finding the Fourth Proportional to 21,321.40, 31,982.10 and 11,990.20

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Solution

The fourth proportional to 21,321.40, 31,982.10 and 11,990.20 is: 17,985.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    21,321.40 : 31,982.10 = 11,990.20 : x
  2. Step 2: Convert to fraction form
    21,321.40/31,982.10 = 11,990.20/x
  3. Step 3: Cross multiply
    21,321.40x = 31,982.10 × 11,990.20
  4. Step 4: Simplify right side
    21,321.40x = 383,471,775.42
  5. Step 5: Solve for x
    x = 383,471,775.42/21,321.40
  6. Step 6: Final answer
    x = 17,985.30

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Similar ratio
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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.