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Finding the Fourth Proportional to 45.31, 67.79 and 39.86

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Solution

The fourth proportional to 45.31, 67.79 and 39.86 is: 59.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    45.31 : 67.79 = 39.86 : x
  2. Step 2: Convert to fraction form
    45.31/67.79 = 39.86/x
  3. Step 3: Cross multiply
    45.31x = 67.79 × 39.86
  4. Step 4: Simplify right side
    45.31x = 2,702.11
  5. Step 5: Solve for x
    x = 2,702.11/45.31
  6. Step 6: Final answer
    x = 59.64

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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.