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Finding the Fourth Proportional to 872.35, 1,309.45 and 439.50

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Solution

The fourth proportional to 872.35, 1,309.45 and 439.50 is: 659.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    872.35 : 1,309.45 = 439.50 : x
  2. Step 2: Convert to fraction form
    872.35/1,309.45 = 439.50/x
  3. Step 3: Cross multiply
    872.35x = 1,309.45 × 439.50
  4. Step 4: Simplify right side
    872.35x = 575,502.18
  5. Step 5: Solve for x
    x = 575,502.18/872.35
  6. Step 6: Final answer
    x = 659.72

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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.