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Finding the Fourth Proportional to 412.99, 619.46 and 139.05

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Solution

The fourth proportional to 412.99, 619.46 and 139.05 is: 208.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    412.99 : 619.46 = 139.05 : x
  2. Step 2: Convert to fraction form
    412.99/619.46 = 139.05/x
  3. Step 3: Cross multiply
    412.99x = 619.46 × 139.05
  4. Step 4: Simplify right side
    412.99x = 86,135.74
  5. Step 5: Solve for x
    x = 86,135.74/412.99
  6. Step 6: Final answer
    x = 208.57

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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.