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Finding the Fourth Proportional to 438.70, 656.70 and 425.20

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Solution

The fourth proportional to 438.70, 656.70 and 425.20 is: 636.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    438.70 : 656.70 = 425.20 : x
  2. Step 2: Convert to fraction form
    438.70/656.70 = 425.20/x
  3. Step 3: Cross multiply
    438.70x = 656.70 × 425.20
  4. Step 4: Simplify right side
    438.70x = 279,228.84
  5. Step 5: Solve for x
    x = 279,228.84/438.70
  6. Step 6: Final answer
    x = 636.49

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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.