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Finding the Fourth Proportional to 90.15, 135.18 and 51.63

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Solution

The fourth proportional to 90.15, 135.18 and 51.63 is: 77.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.15 : 135.18 = 51.63 : x
  2. Step 2: Convert to fraction form
    90.15/135.18 = 51.63/x
  3. Step 3: Cross multiply
    90.15x = 135.18 × 51.63
  4. Step 4: Simplify right side
    90.15x = 6,979.34
  5. Step 5: Solve for x
    x = 6,979.34/90.15
  6. Step 6: Final answer
    x = 77.42

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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.