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Finding the Fourth Proportional to 814.28, 1,123.72 and 499.42

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Solution

The fourth proportional to 814.28, 1,123.72 and 499.42 is: 689.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    814.28 : 1,123.72 = 499.42 : x
  2. Step 2: Convert to fraction form
    814.28/1,123.72 = 499.42/x
  3. Step 3: Cross multiply
    814.28x = 1,123.72 × 499.42
  4. Step 4: Simplify right side
    814.28x = 561,208.24
  5. Step 5: Solve for x
    x = 561,208.24/814.28
  6. Step 6: Final answer
    x = 689.21

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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.