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Finding the Fourth Proportional to 405.72, 609.12 and 210.87

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Solution

The fourth proportional to 405.72, 609.12 and 210.87 is: 316.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.72 : 609.12 = 210.87 : x
  2. Step 2: Convert to fraction form
    405.72/609.12 = 210.87/x
  3. Step 3: Cross multiply
    405.72x = 609.12 × 210.87
  4. Step 4: Simplify right side
    405.72x = 128,445.13
  5. Step 5: Solve for x
    x = 128,445.13/405.72
  6. Step 6: Final answer
    x = 316.59

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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.