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Finding the Fourth Proportional to 84.88, 126.53 and 81.28

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Solution

The fourth proportional to 84.88, 126.53 and 81.28 is: 121.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.88 : 126.53 = 81.28 : x
  2. Step 2: Convert to fraction form
    84.88/126.53 = 81.28/x
  3. Step 3: Cross multiply
    84.88x = 126.53 × 81.28
  4. Step 4: Simplify right side
    84.88x = 10,284.36
  5. Step 5: Solve for x
    x = 10,284.36/84.88
  6. Step 6: Final answer
    x = 121.16

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.