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Finding the Fourth Proportional to 84.90, 127.47 and 80.98

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Solution

The fourth proportional to 84.90, 127.47 and 80.98 is: 121.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.90 : 127.47 = 80.98 : x
  2. Step 2: Convert to fraction form
    84.90/127.47 = 80.98/x
  3. Step 3: Cross multiply
    84.90x = 127.47 × 80.98
  4. Step 4: Simplify right side
    84.90x = 10,322.52
  5. Step 5: Solve for x
    x = 10,322.52/84.90
  6. Step 6: Final answer
    x = 121.58

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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.