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Finding the Fourth Proportional to 90.45, 135.68 and 21.98

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Solution

The fourth proportional to 90.45, 135.68 and 21.98 is: 32.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.45 : 135.68 = 21.98 : x
  2. Step 2: Convert to fraction form
    90.45/135.68 = 21.98/x
  3. Step 3: Cross multiply
    90.45x = 135.68 × 21.98
  4. Step 4: Simplify right side
    90.45x = 2,981.92
  5. Step 5: Solve for x
    x = 2,981.92/90.45
  6. Step 6: Final answer
    x = 32.97

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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.