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Finding the Fourth Proportional to 90.53, 135.81 and 78.22

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Solution

The fourth proportional to 90.53, 135.81 and 78.22 is: 117.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.53 : 135.81 = 78.22 : x
  2. Step 2: Convert to fraction form
    90.53/135.81 = 78.22/x
  3. Step 3: Cross multiply
    90.53x = 135.81 × 78.22
  4. Step 4: Simplify right side
    90.53x = 10,622.67
  5. Step 5: Solve for x
    x = 10,622.67/90.53
  6. Step 6: Final answer
    x = 117.34

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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.