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Finding the Fourth Proportional to 115.39, 159.07 and 84.21

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Solution

The fourth proportional to 115.39, 159.07 and 84.21 is: 116.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    115.39 : 159.07 = 84.21 : x
  2. Step 2: Convert to fraction form
    115.39/159.07 = 84.21/x
  3. Step 3: Cross multiply
    115.39x = 159.07 × 84.21
  4. Step 4: Simplify right side
    115.39x = 13,395.28
  5. Step 5: Solve for x
    x = 13,395.28/115.39
  6. Step 6: Final answer
    x = 116.09

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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.