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Finding the Fourth Proportional to 115.29, 159.20 and 78.58

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Solution

The fourth proportional to 115.29, 159.20 and 78.58 is: 108.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    115.29 : 159.20 = 78.58 : x
  2. Step 2: Convert to fraction form
    115.29/159.20 = 78.58/x
  3. Step 3: Cross multiply
    115.29x = 159.20 × 78.58
  4. Step 4: Simplify right side
    115.29x = 12,509.94
  5. Step 5: Solve for x
    x = 12,509.94/115.29
  6. Step 6: Final answer
    x = 108.51

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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.