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Finding the Fourth Proportional to 107.58, 161.21 and 77.21

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Solution

The fourth proportional to 107.58, 161.21 and 77.21 is: 115.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    107.58 : 161.21 = 77.21 : x
  2. Step 2: Convert to fraction form
    107.58/161.21 = 77.21/x
  3. Step 3: Cross multiply
    107.58x = 161.21 × 77.21
  4. Step 4: Simplify right side
    107.58x = 12,447.02
  5. Step 5: Solve for x
    x = 12,447.02/107.58
  6. Step 6: Final answer
    x = 115.70

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.