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Finding the Fourth Proportional to 98.40, 136.80 and 98.40

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Solution

The fourth proportional to 98.40, 136.80 and 98.40 is: 136.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    98.40 : 136.80 = 98.40 : x
  2. Step 2: Convert to fraction form
    98.40/136.80 = 98.40/x
  3. Step 3: Cross multiply
    98.40x = 136.80 × 98.40
  4. Step 4: Simplify right side
    98.40x = 13,461.12
  5. Step 5: Solve for x
    x = 13,461.12/98.40
  6. Step 6: Final answer
    x = 136.80

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.