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Finding the Fourth Proportional to 90.81, 136.08 and 45.19

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Solution

The fourth proportional to 90.81, 136.08 and 45.19 is: 67.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.81 : 136.08 = 45.19 : x
  2. Step 2: Convert to fraction form
    90.81/136.08 = 45.19/x
  3. Step 3: Cross multiply
    90.81x = 136.08 × 45.19
  4. Step 4: Simplify right side
    90.81x = 6,148.77
  5. Step 5: Solve for x
    x = 6,148.77/90.81
  6. Step 6: Final answer
    x = 67.71

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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.