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Finding the Fourth Proportional to 60.78, 91.05 and 39.09

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Solution

The fourth proportional to 60.78, 91.05 and 39.09 is: 58.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    60.78 : 91.05 = 39.09 : x
  2. Step 2: Convert to fraction form
    60.78/91.05 = 39.09/x
  3. Step 3: Cross multiply
    60.78x = 91.05 × 39.09
  4. Step 4: Simplify right side
    60.78x = 3,559.14
  5. Step 5: Solve for x
    x = 3,559.14/60.78
  6. Step 6: Final answer
    x = 58.56

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.