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Finding the Fourth Proportional to 85.74, 127.55 and 84.87

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Solution

The fourth proportional to 85.74, 127.55 and 84.87 is: 126.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.74 : 127.55 = 84.87 : x
  2. Step 2: Convert to fraction form
    85.74/127.55 = 84.87/x
  3. Step 3: Cross multiply
    85.74x = 127.55 × 84.87
  4. Step 4: Simplify right side
    85.74x = 10,824.74
  5. Step 5: Solve for x
    x = 10,824.74/85.74
  6. Step 6: Final answer
    x = 126.25

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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.