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Finding the Fourth Proportional to 137.28, 189.18 and 98.40

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Solution

The fourth proportional to 137.28, 189.18 and 98.40 is: 135.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.28 : 189.18 = 98.40 : x
  2. Step 2: Convert to fraction form
    137.28/189.18 = 98.40/x
  3. Step 3: Cross multiply
    137.28x = 189.18 × 98.40
  4. Step 4: Simplify right side
    137.28x = 18,615.31
  5. Step 5: Solve for x
    x = 18,615.31/137.28
  6. Step 6: Final answer
    x = 135.60

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.