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Finding the Fourth Proportional to 816.30, 1,223.04 and 687.15

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Solution

The fourth proportional to 816.30, 1,223.04 and 687.15 is: 1,029.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    816.30 : 1,223.04 = 687.15 : x
  2. Step 2: Convert to fraction form
    816.30/1,223.04 = 687.15/x
  3. Step 3: Cross multiply
    816.30x = 1,223.04 × 687.15
  4. Step 4: Simplify right side
    816.30x = 840,411.94
  5. Step 5: Solve for x
    x = 840,411.94/816.30
  6. Step 6: Final answer
    x = 1,029.54

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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.