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Finding the Fourth Proportional to 1,209.44, 1,813.90 and 387.78

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Solution

The fourth proportional to 1,209.44, 1,813.90 and 387.78 is: 581.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,209.44 : 1,813.90 = 387.78 : x
  2. Step 2: Convert to fraction form
    1,209.44/1,813.90 = 387.78/x
  3. Step 3: Cross multiply
    1,209.44x = 1,813.90 × 387.78
  4. Step 4: Simplify right side
    1,209.44x = 703,394.14
  5. Step 5: Solve for x
    x = 703,394.14/1,209.44
  6. Step 6: Final answer
    x = 581.59

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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.