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Finding the Fourth Proportional to 720.21, 1,081.39 and 412.41

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Solution

The fourth proportional to 720.21, 1,081.39 and 412.41 is: 619.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.21 : 1,081.39 = 412.41 : x
  2. Step 2: Convert to fraction form
    720.21/1,081.39 = 412.41/x
  3. Step 3: Cross multiply
    720.21x = 1,081.39 × 412.41
  4. Step 4: Simplify right side
    720.21x = 445,969.61
  5. Step 5: Solve for x
    x = 445,969.61/720.21
  6. Step 6: Final answer
    x = 619.23

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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.