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Finding the Fourth Proportional to 1,209.60, 1,814.40 and 429.84

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Solution

The fourth proportional to 1,209.60, 1,814.40 and 429.84 is: 644.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,209.60 : 1,814.40 = 429.84 : x
  2. Step 2: Convert to fraction form
    1,209.60/1,814.40 = 429.84/x
  3. Step 3: Cross multiply
    1,209.60x = 1,814.40 × 429.84
  4. Step 4: Simplify right side
    1,209.60x = 779,901.70
  5. Step 5: Solve for x
    x = 779,901.70/1,209.60
  6. Step 6: Final answer
    x = 644.76

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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.