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Finding the Fourth Proportional to 438.05, 656.98 and 387.43

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Solution

The fourth proportional to 438.05, 656.98 and 387.43 is: 581.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    438.05 : 656.98 = 387.43 : x
  2. Step 2: Convert to fraction form
    438.05/656.98 = 387.43/x
  3. Step 3: Cross multiply
    438.05x = 656.98 × 387.43
  4. Step 4: Simplify right side
    438.05x = 254,533.76
  5. Step 5: Solve for x
    x = 254,533.76/438.05
  6. Step 6: Final answer
    x = 581.06

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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.