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Finding the Fourth Proportional to 817.90, 1,128.53 and 486.10

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Solution

The fourth proportional to 817.90, 1,128.53 and 486.10 is: 670.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    817.90 : 1,128.53 = 486.10 : x
  2. Step 2: Convert to fraction form
    817.90/1,128.53 = 486.10/x
  3. Step 3: Cross multiply
    817.90x = 1,128.53 × 486.10
  4. Step 4: Simplify right side
    817.90x = 548,581.06
  5. Step 5: Solve for x
    x = 548,581.06/817.90
  6. Step 6: Final answer
    x = 670.72

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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.