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Finding the Fourth Proportional to 90.87, 136.30 and 70.59

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Solution

The fourth proportional to 90.87, 136.30 and 70.59 is: 105.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.87 : 136.30 = 70.59 : x
  2. Step 2: Convert to fraction form
    90.87/136.30 = 70.59/x
  3. Step 3: Cross multiply
    90.87x = 136.30 × 70.59
  4. Step 4: Simplify right side
    90.87x = 9,621.42
  5. Step 5: Solve for x
    x = 9,621.42/90.87
  6. Step 6: Final answer
    x = 105.88

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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.