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Finding the Fourth Proportional to 817.64, 1,128.26 and 486.15

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Solution

The fourth proportional to 817.64, 1,128.26 and 486.15 is: 670.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    817.64 : 1,128.26 = 486.15 : x
  2. Step 2: Convert to fraction form
    817.64/1,128.26 = 486.15/x
  3. Step 3: Cross multiply
    817.64x = 1,128.26 × 486.15
  4. Step 4: Simplify right side
    817.64x = 548,500.58
  5. Step 5: Solve for x
    x = 548,500.58/817.64
  6. Step 6: Final answer
    x = 670.83

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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.