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Finding the Fourth Proportional to 819.78, 1,130.81 and 488.15

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Solution

The fourth proportional to 819.78, 1,130.81 and 488.15 is: 673.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.78 : 1,130.81 = 488.15 : x
  2. Step 2: Convert to fraction form
    819.78/1,130.81 = 488.15/x
  3. Step 3: Cross multiply
    819.78x = 1,130.81 × 488.15
  4. Step 4: Simplify right side
    819.78x = 552,004.90
  5. Step 5: Solve for x
    x = 552,004.90/819.78
  6. Step 6: Final answer
    x = 673.36

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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.