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Finding the Fourth Proportional to 479.87, 661.86 and 311.86

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Solution

The fourth proportional to 479.87, 661.86 and 311.86 is: 430.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    479.87 : 661.86 = 311.86 : x
  2. Step 2: Convert to fraction form
    479.87/661.86 = 311.86/x
  3. Step 3: Cross multiply
    479.87x = 661.86 × 311.86
  4. Step 4: Simplify right side
    479.87x = 206,407.66
  5. Step 5: Solve for x
    x = 206,407.66/479.87
  6. Step 6: Final answer
    x = 430.14

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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.