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Finding the Fourth Proportional to 438.45, 660.26 and 317.55

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Solution

The fourth proportional to 438.45, 660.26 and 317.55 is: 478.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    438.45 : 660.26 = 317.55 : x
  2. Step 2: Convert to fraction form
    438.45/660.26 = 317.55/x
  3. Step 3: Cross multiply
    438.45x = 660.26 × 317.55
  4. Step 4: Simplify right side
    438.45x = 209,665.56
  5. Step 5: Solve for x
    x = 209,665.56/438.45
  6. Step 6: Final answer
    x = 478.20

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.