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Finding the Fourth Proportional to 61.09, 91.20 and 57.09

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Solution

The fourth proportional to 61.09, 91.20 and 57.09 is: 85.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    61.09 : 91.20 = 57.09 : x
  2. Step 2: Convert to fraction form
    61.09/91.20 = 57.09/x
  3. Step 3: Cross multiply
    61.09x = 91.20 × 57.09
  4. Step 4: Simplify right side
    61.09x = 5,206.61
  5. Step 5: Solve for x
    x = 5,206.61/61.09
  6. Step 6: Final answer
    x = 85.23

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.