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Finding the Fourth Proportional to 819.48, 1,130.43 and 487.80

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Solution

The fourth proportional to 819.48, 1,130.43 and 487.80 is: 672.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.48 : 1,130.43 = 487.80 : x
  2. Step 2: Convert to fraction form
    819.48/1,130.43 = 487.80/x
  3. Step 3: Cross multiply
    819.48x = 1,130.43 × 487.80
  4. Step 4: Simplify right side
    819.48x = 551,423.75
  5. Step 5: Solve for x
    x = 551,423.75/819.48
  6. Step 6: Final answer
    x = 672.89

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.