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Finding the Fourth Proportional to 90.86, 135.57 and 72.37

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Solution

The fourth proportional to 90.86, 135.57 and 72.37 is: 107.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.86 : 135.57 = 72.37 : x
  2. Step 2: Convert to fraction form
    90.86/135.57 = 72.37/x
  3. Step 3: Cross multiply
    90.86x = 135.57 × 72.37
  4. Step 4: Simplify right side
    90.86x = 9,811.20
  5. Step 5: Solve for x
    x = 9,811.20/90.86
  6. Step 6: Final answer
    x = 107.98

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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.