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Finding the Fourth Proportional to 817.91, 1,223.79 and 487.63

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Solution

The fourth proportional to 817.91, 1,223.79 and 487.63 is: 729.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    817.91 : 1,223.79 = 487.63 : x
  2. Step 2: Convert to fraction form
    817.91/1,223.79 = 487.63/x
  3. Step 3: Cross multiply
    817.91x = 1,223.79 × 487.63
  4. Step 4: Simplify right side
    817.91x = 596,756.72
  5. Step 5: Solve for x
    x = 596,756.72/817.91
  6. Step 6: Final answer
    x = 729.61

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.