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Finding the Fourth Proportional to 65.91, 91.13 and 57.71

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Solution

The fourth proportional to 65.91, 91.13 and 57.71 is: 79.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    65.91 : 91.13 = 57.71 : x
  2. Step 2: Convert to fraction form
    65.91/91.13 = 57.71/x
  3. Step 3: Cross multiply
    65.91x = 91.13 × 57.71
  4. Step 4: Simplify right side
    65.91x = 5,259.05
  5. Step 5: Solve for x
    x = 5,259.05/65.91
  6. Step 6: Final answer
    x = 79.79

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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.