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Finding the Fourth Proportional to 817.79, 1,128.17 and 486.09

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Solution

The fourth proportional to 817.79, 1,128.17 and 486.09 is: 670.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    817.79 : 1,128.17 = 486.09 : x
  2. Step 2: Convert to fraction form
    817.79/1,128.17 = 486.09/x
  3. Step 3: Cross multiply
    817.79x = 1,128.17 × 486.09
  4. Step 4: Simplify right side
    817.79x = 548,389.72
  5. Step 5: Solve for x
    x = 548,389.72/817.79
  6. Step 6: Final answer
    x = 670.58

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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.