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Finding the Fourth Proportional to 115.39, 159.21 and 76.57

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Solution

The fourth proportional to 115.39, 159.21 and 76.57 is: 105.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    115.39 : 159.21 = 76.57 : x
  2. Step 2: Convert to fraction form
    115.39/159.21 = 76.57/x
  3. Step 3: Cross multiply
    115.39x = 159.21 × 76.57
  4. Step 4: Simplify right side
    115.39x = 12,190.71
  5. Step 5: Solve for x
    x = 12,190.71/115.39
  6. Step 6: Final answer
    x = 105.65

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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.