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Finding the Fourth Proportional to 84.15, 116.07 and 57.90

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Solution

The fourth proportional to 84.15, 116.07 and 57.90 is: 79.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.15 : 116.07 = 57.90 : x
  2. Step 2: Convert to fraction form
    84.15/116.07 = 57.90/x
  3. Step 3: Cross multiply
    84.15x = 116.07 × 57.90
  4. Step 4: Simplify right side
    84.15x = 6,720.67
  5. Step 5: Solve for x
    x = 6,720.67/84.15
  6. Step 6: Final answer
    x = 79.87

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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.