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Finding the Fourth Proportional to 98.70, 138.45 and 98.70

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Solution

The fourth proportional to 98.70, 138.45 and 98.70 is: 138.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    98.70 : 138.45 = 98.70 : x
  2. Step 2: Convert to fraction form
    98.70/138.45 = 98.70/x
  3. Step 3: Cross multiply
    98.70x = 138.45 × 98.70
  4. Step 4: Simplify right side
    98.70x = 13,665.02
  5. Step 5: Solve for x
    x = 13,665.02/98.70
  6. Step 6: Final answer
    x = 138.45

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Why These Related Problems?

These problems maintain the same ratio (1.40) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.