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Finding the Fourth Proportional to 499.78, 689.49 and 331.81

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Solution

The fourth proportional to 499.78, 689.49 and 331.81 is: 457.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    499.78 : 689.49 = 331.81 : x
  2. Step 2: Convert to fraction form
    499.78/689.49 = 331.81/x
  3. Step 3: Cross multiply
    499.78x = 689.49 × 331.81
  4. Step 4: Simplify right side
    499.78x = 228,782.86
  5. Step 5: Solve for x
    x = 228,782.86/499.78
  6. Step 6: Final answer
    x = 457.77

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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.