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Finding the Fourth Proportional to 84.05, 115.87 and 57.77

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Solution

The fourth proportional to 84.05, 115.87 and 57.77 is: 79.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.05 : 115.87 = 57.77 : x
  2. Step 2: Convert to fraction form
    84.05/115.87 = 57.77/x
  3. Step 3: Cross multiply
    84.05x = 115.87 × 57.77
  4. Step 4: Simplify right side
    84.05x = 6,693.74
  5. Step 5: Solve for x
    x = 6,693.74/84.05
  6. Step 6: Final answer
    x = 79.64

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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.