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Finding the Fourth Proportional to 312.20, 468.28 and 138.88

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Solution

The fourth proportional to 312.20, 468.28 and 138.88 is: 208.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.20 : 468.28 = 138.88 : x
  2. Step 2: Convert to fraction form
    312.20/468.28 = 138.88/x
  3. Step 3: Cross multiply
    312.20x = 468.28 × 138.88
  4. Step 4: Simplify right side
    312.20x = 65,033.51
  5. Step 5: Solve for x
    x = 65,033.51/312.20
  6. Step 6: Final answer
    x = 208.30

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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.