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Finding the Fourth Proportional to 61.79, 85.76 and 57.74

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Solution

The fourth proportional to 61.79, 85.76 and 57.74 is: 80.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    61.79 : 85.76 = 57.74 : x
  2. Step 2: Convert to fraction form
    61.79/85.76 = 57.74/x
  3. Step 3: Cross multiply
    61.79x = 85.76 × 57.74
  4. Step 4: Simplify right side
    61.79x = 4,951.06
  5. Step 5: Solve for x
    x = 4,951.06/61.79
  6. Step 6: Final answer
    x = 80.13

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.