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Finding the Fourth Proportional to 90.10, 135.04 and 78.12

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Solution

The fourth proportional to 90.10, 135.04 and 78.12 is: 117.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.10 : 135.04 = 78.12 : x
  2. Step 2: Convert to fraction form
    90.10/135.04 = 78.12/x
  3. Step 3: Cross multiply
    90.10x = 135.04 × 78.12
  4. Step 4: Simplify right side
    90.10x = 10,549.32
  5. Step 5: Solve for x
    x = 10,549.32/90.10
  6. Step 6: Final answer
    x = 117.08

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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.