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Finding the Fourth Proportional to 499.36, 688.43 and 420.99

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Solution

The fourth proportional to 499.36, 688.43 and 420.99 is: 580.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    499.36 : 688.43 = 420.99 : x
  2. Step 2: Convert to fraction form
    499.36/688.43 = 420.99/x
  3. Step 3: Cross multiply
    499.36x = 688.43 × 420.99
  4. Step 4: Simplify right side
    499.36x = 289,820.04
  5. Step 5: Solve for x
    x = 289,820.04/499.36
  6. Step 6: Final answer
    x = 580.39

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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.