Home / 20,881.80-31,322.70-12,139.20

Finding the Fourth Proportional to 20,881.80, 31,322.70 and 12,139.20

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Solution

The fourth proportional to 20,881.80, 31,322.70 and 12,139.20 is: 18,208.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    20,881.80 : 31,322.70 = 12,139.20 : x
  2. Step 2: Convert to fraction form
    20,881.80/31,322.70 = 12,139.20/x
  3. Step 3: Cross multiply
    20,881.80x = 31,322.70 × 12,139.20
  4. Step 4: Simplify right side
    20,881.80x = 380,232,519.84
  5. Step 5: Solve for x
    x = 380,232,519.84/20,881.80
  6. Step 6: Final answer
    x = 18,208.80

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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.