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Finding the Fourth Proportional to 438.38, 656.20 and 321

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Solution

The fourth proportional to 438.38, 656.20 and 321 is: 480.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    438.38 : 656.20 = 321 : x
  2. Step 2: Convert to fraction form
    438.38/656.20 = 321/x
  3. Step 3: Cross multiply
    438.38x = 656.20 × 321
  4. Step 4: Simplify right side
    438.38x = 210,640.20
  5. Step 5: Solve for x
    x = 210,640.20/438.38
  6. Step 6: Final answer
    x = 480.50

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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.