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Finding the Fourth Proportional to 84.71, 126.80 and 54.30

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Solution

The fourth proportional to 84.71, 126.80 and 54.30 is: 81.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.71 : 126.80 = 54.30 : x
  2. Step 2: Convert to fraction form
    84.71/126.80 = 54.30/x
  3. Step 3: Cross multiply
    84.71x = 126.80 × 54.30
  4. Step 4: Simplify right side
    84.71x = 6,885.69
  5. Step 5: Solve for x
    x = 6,885.69/84.71
  6. Step 6: Final answer
    x = 81.29

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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.