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Finding the Fourth Proportional to 65.91, 91.03 and 57.70

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Solution

The fourth proportional to 65.91, 91.03 and 57.70 is: 79.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    65.91 : 91.03 = 57.70 : x
  2. Step 2: Convert to fraction form
    65.91/91.03 = 57.70/x
  3. Step 3: Cross multiply
    65.91x = 91.03 × 57.70
  4. Step 4: Simplify right side
    65.91x = 5,251.98
  5. Step 5: Solve for x
    x = 5,251.98/65.91
  6. Step 6: Final answer
    x = 79.68

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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.