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Finding the Fourth Proportional to 819.30, 1,130.69 and 487.74

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Solution

The fourth proportional to 819.30, 1,130.69 and 487.74 is: 673.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.30 : 1,130.69 = 487.74 : x
  2. Step 2: Convert to fraction form
    819.30/1,130.69 = 487.74/x
  3. Step 3: Cross multiply
    819.30x = 1,130.69 × 487.74
  4. Step 4: Simplify right side
    819.30x = 551,482.74
  5. Step 5: Solve for x
    x = 551,482.74/819.30
  6. Step 6: Final answer
    x = 673.11

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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.