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Finding the Fourth Proportional to 499.42, 748.71 and 390.86

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Solution

The fourth proportional to 499.42, 748.71 and 390.86 is: 585.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    499.42 : 748.71 = 390.86 : x
  2. Step 2: Convert to fraction form
    499.42/748.71 = 390.86/x
  3. Step 3: Cross multiply
    499.42x = 748.71 × 390.86
  4. Step 4: Simplify right side
    499.42x = 292,640.79
  5. Step 5: Solve for x
    x = 292,640.79/499.42
  6. Step 6: Final answer
    x = 585.96

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.