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Finding the Fourth Proportional to 90.30, 134.56 and 87.39

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Solution

The fourth proportional to 90.30, 134.56 and 87.39 is: 130.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.30 : 134.56 = 87.39 : x
  2. Step 2: Convert to fraction form
    90.30/134.56 = 87.39/x
  3. Step 3: Cross multiply
    90.30x = 134.56 × 87.39
  4. Step 4: Simplify right side
    90.30x = 11,759.20
  5. Step 5: Solve for x
    x = 11,759.20/90.30
  6. Step 6: Final answer
    x = 130.22

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.