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Finding the Fourth Proportional to 813.72, 1,122.30 and 498.72

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Solution

The fourth proportional to 813.72, 1,122.30 and 498.72 is: 687.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    813.72 : 1,122.30 = 498.72 : x
  2. Step 2: Convert to fraction form
    813.72/1,122.30 = 498.72/x
  3. Step 3: Cross multiply
    813.72x = 1,122.30 × 498.72
  4. Step 4: Simplify right side
    813.72x = 559,713.46
  5. Step 5: Solve for x
    x = 559,713.46/813.72
  6. Step 6: Final answer
    x = 687.85

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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.