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Finding the Fourth Proportional to 478.71, 660.50 and 312.86

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Solution

The fourth proportional to 478.71, 660.50 and 312.86 is: 431.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    478.71 : 660.50 = 312.86 : x
  2. Step 2: Convert to fraction form
    478.71/660.50 = 312.86/x
  3. Step 3: Cross multiply
    478.71x = 660.50 × 312.86
  4. Step 4: Simplify right side
    478.71x = 206,647.05
  5. Step 5: Solve for x
    x = 206,647.05/478.71
  6. Step 6: Final answer
    x = 431.67

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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.