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Finding the Fourth Proportional to 499.12, 688.78 and 289.36

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Solution

The fourth proportional to 499.12, 688.78 and 289.36 is: 399.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    499.12 : 688.78 = 289.36 : x
  2. Step 2: Convert to fraction form
    499.12/688.78 = 289.36/x
  3. Step 3: Cross multiply
    499.12x = 688.78 × 289.36
  4. Step 4: Simplify right side
    499.12x = 199,305.38
  5. Step 5: Solve for x
    x = 199,305.38/499.12
  6. Step 6: Final answer
    x = 399.31

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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.