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Finding the Fourth Proportional to 90.38, 135.68 and 66.05

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Solution

The fourth proportional to 90.38, 135.68 and 66.05 is: 99.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.38 : 135.68 = 66.05 : x
  2. Step 2: Convert to fraction form
    90.38/135.68 = 66.05/x
  3. Step 3: Cross multiply
    90.38x = 135.68 × 66.05
  4. Step 4: Simplify right side
    90.38x = 8,960.66
  5. Step 5: Solve for x
    x = 8,960.66/90.38
  6. Step 6: Final answer
    x = 99.14

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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.