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Finding the Fourth Proportional to 98.70, 148.20 and 84.30

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Solution

The fourth proportional to 98.70, 148.20 and 84.30 is: 126.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    98.70 : 148.20 = 84.30 : x
  2. Step 2: Convert to fraction form
    98.70/148.20 = 84.30/x
  3. Step 3: Cross multiply
    98.70x = 148.20 × 84.30
  4. Step 4: Simplify right side
    98.70x = 12,493.26
  5. Step 5: Solve for x
    x = 12,493.26/98.70
  6. Step 6: Final answer
    x = 126.58

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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.