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Finding the Fourth Proportional to 511.55, 768.34 and 438.40

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Solution

The fourth proportional to 511.55, 768.34 and 438.40 is: 658.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    511.55 : 768.34 = 438.40 : x
  2. Step 2: Convert to fraction form
    511.55/768.34 = 438.40/x
  3. Step 3: Cross multiply
    511.55x = 768.34 × 438.40
  4. Step 4: Simplify right side
    511.55x = 336,840.26
  5. Step 5: Solve for x
    x = 336,840.26/511.55
  6. Step 6: Final answer
    x = 658.47

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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.