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Finding the Fourth Proportional to 90.05, 135.09 and 76.28

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Solution

The fourth proportional to 90.05, 135.09 and 76.28 is: 114.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.05 : 135.09 = 76.28 : x
  2. Step 2: Convert to fraction form
    90.05/135.09 = 76.28/x
  3. Step 3: Cross multiply
    90.05x = 135.09 × 76.28
  4. Step 4: Simplify right side
    90.05x = 10,303.99
  5. Step 5: Solve for x
    x = 10,303.99/90.05
  6. Step 6: Final answer
    x = 114.43

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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.