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Finding the Fourth Proportional to 115.20, 159.08 and 90.75

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Solution

The fourth proportional to 115.20, 159.08 and 90.75 is: 125.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    115.20 : 159.08 = 90.75 : x
  2. Step 2: Convert to fraction form
    115.20/159.08 = 90.75/x
  3. Step 3: Cross multiply
    115.20x = 159.08 × 90.75
  4. Step 4: Simplify right side
    115.20x = 14,436.06
  5. Step 5: Solve for x
    x = 14,436.06/115.20
  6. Step 6: Final answer
    x = 125.31

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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.