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Finding the Fourth Proportional to 386.80, 580.32 and 112.90

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Solution

The fourth proportional to 386.80, 580.32 and 112.90 is: 169.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.80 : 580.32 = 112.90 : x
  2. Step 2: Convert to fraction form
    386.80/580.32 = 112.90/x
  3. Step 3: Cross multiply
    386.80x = 580.32 × 112.90
  4. Step 4: Simplify right side
    386.80x = 65,518.13
  5. Step 5: Solve for x
    x = 65,518.13/386.80
  6. Step 6: Final answer
    x = 169.39

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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.