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Finding the Fourth Proportional to 115.09, 158.81 and 78.19

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Solution

The fourth proportional to 115.09, 158.81 and 78.19 is: 107.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    115.09 : 158.81 = 78.19 : x
  2. Step 2: Convert to fraction form
    115.09/158.81 = 78.19/x
  3. Step 3: Cross multiply
    115.09x = 158.81 × 78.19
  4. Step 4: Simplify right side
    115.09x = 12,417.35
  5. Step 5: Solve for x
    x = 12,417.35/115.09
  6. Step 6: Final answer
    x = 107.89

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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.