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Finding the Fourth Proportional to 90.59, 136.08 and 86.36

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Solution

The fourth proportional to 90.59, 136.08 and 86.36 is: 129.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.59 : 136.08 = 86.36 : x
  2. Step 2: Convert to fraction form
    90.59/136.08 = 86.36/x
  3. Step 3: Cross multiply
    90.59x = 136.08 × 86.36
  4. Step 4: Simplify right side
    90.59x = 11,751.19
  5. Step 5: Solve for x
    x = 11,751.19/90.59
  6. Step 6: Final answer
    x = 129.73

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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.