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Finding the Fourth Proportional to 480.40, 720.56 and 138.40

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Solution

The fourth proportional to 480.40, 720.56 and 138.40 is: 207.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    480.40 : 720.56 = 138.40 : x
  2. Step 2: Convert to fraction form
    480.40/720.56 = 138.40/x
  3. Step 3: Cross multiply
    480.40x = 720.56 × 138.40
  4. Step 4: Simplify right side
    480.40x = 99,725.50
  5. Step 5: Solve for x
    x = 99,725.50/480.40
  6. Step 6: Final answer
    x = 207.59

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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.