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Finding the Fourth Proportional to 85.29, 127.28 and 76.20

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Solution

The fourth proportional to 85.29, 127.28 and 76.20 is: 113.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.29 : 127.28 = 76.20 : x
  2. Step 2: Convert to fraction form
    85.29/127.28 = 76.20/x
  3. Step 3: Cross multiply
    85.29x = 127.28 × 76.20
  4. Step 4: Simplify right side
    85.29x = 9,698.74
  5. Step 5: Solve for x
    x = 9,698.74/85.29
  6. Step 6: Final answer
    x = 113.71

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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.