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Finding the Fourth Proportional to 98.48, 135.88 and 90.80

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Solution

The fourth proportional to 98.48, 135.88 and 90.80 is: 125.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    98.48 : 135.88 = 90.80 : x
  2. Step 2: Convert to fraction form
    98.48/135.88 = 90.80/x
  3. Step 3: Cross multiply
    98.48x = 135.88 × 90.80
  4. Step 4: Simplify right side
    98.48x = 12,337.90
  5. Step 5: Solve for x
    x = 12,337.90/98.48
  6. Step 6: Final answer
    x = 125.28

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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.