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Finding the Fourth Proportional to 84.76, 126.53 and 77.20

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Solution

The fourth proportional to 84.76, 126.53 and 77.20 is: 115.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.76 : 126.53 = 77.20 : x
  2. Step 2: Convert to fraction form
    84.76/126.53 = 77.20/x
  3. Step 3: Cross multiply
    84.76x = 126.53 × 77.20
  4. Step 4: Simplify right side
    84.76x = 9,768.12
  5. Step 5: Solve for x
    x = 9,768.12/84.76
  6. Step 6: Final answer
    x = 115.24

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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.