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Finding the Fourth Proportional to 90.56, 135.78 and 47.22

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Solution

The fourth proportional to 90.56, 135.78 and 47.22 is: 70.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.56 : 135.78 = 47.22 : x
  2. Step 2: Convert to fraction form
    90.56/135.78 = 47.22/x
  3. Step 3: Cross multiply
    90.56x = 135.78 × 47.22
  4. Step 4: Simplify right side
    90.56x = 6,411.53
  5. Step 5: Solve for x
    x = 6,411.53/90.56
  6. Step 6: Final answer
    x = 70.80

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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.