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Finding the Fourth Proportional to 115.40, 159.30 and 85.88

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Solution

The fourth proportional to 115.40, 159.30 and 85.88 is: 118.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    115.40 : 159.30 = 85.88 : x
  2. Step 2: Convert to fraction form
    115.40/159.30 = 85.88/x
  3. Step 3: Cross multiply
    115.40x = 159.30 × 85.88
  4. Step 4: Simplify right side
    115.40x = 13,680.68
  5. Step 5: Solve for x
    x = 13,680.68/115.40
  6. Step 6: Final answer
    x = 118.55

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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.