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Finding the Fourth Proportional to 499.90, 689.92 and 381.66

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Solution

The fourth proportional to 499.90, 689.92 and 381.66 is: 526.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    499.90 : 689.92 = 381.66 : x
  2. Step 2: Convert to fraction form
    499.90/689.92 = 381.66/x
  3. Step 3: Cross multiply
    499.90x = 689.92 × 381.66
  4. Step 4: Simplify right side
    499.90x = 263,314.87
  5. Step 5: Solve for x
    x = 263,314.87/499.90
  6. Step 6: Final answer
    x = 526.74

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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.