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Finding the Fourth Proportional to 115.10, 159 and 90.85

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Solution

The fourth proportional to 115.10, 159 and 90.85 is: 125.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    115.10 : 159 = 90.85 : x
  2. Step 2: Convert to fraction form
    115.10/159 = 90.85/x
  3. Step 3: Cross multiply
    115.10x = 159 × 90.85
  4. Step 4: Simplify right side
    115.10x = 14,445.15
  5. Step 5: Solve for x
    x = 14,445.15/115.10
  6. Step 6: Final answer
    x = 125.50

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.