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Finding the Fourth Proportional to 90.16, 135.86 and 86.12

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Solution

The fourth proportional to 90.16, 135.86 and 86.12 is: 129.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.16 : 135.86 = 86.12 : x
  2. Step 2: Convert to fraction form
    90.16/135.86 = 86.12/x
  3. Step 3: Cross multiply
    90.16x = 135.86 × 86.12
  4. Step 4: Simplify right side
    90.16x = 11,700.26
  5. Step 5: Solve for x
    x = 11,700.26/90.16
  6. Step 6: Final answer
    x = 129.77

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.