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Finding the Fourth Proportional to 1,209.18, 1,809.64 and 839.10

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Solution

The fourth proportional to 1,209.18, 1,809.64 and 839.10 is: 1,255.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,209.18 : 1,809.64 = 839.10 : x
  2. Step 2: Convert to fraction form
    1,209.18/1,809.64 = 839.10/x
  3. Step 3: Cross multiply
    1,209.18x = 1,809.64 × 839.10
  4. Step 4: Simplify right side
    1,209.18x = 1,518,468.92
  5. Step 5: Solve for x
    x = 1,518,468.92/1,209.18
  6. Step 6: Final answer
    x = 1,255.78

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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.