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Finding the Fourth Proportional to 720.08, 993.60 and 405.34

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Solution

The fourth proportional to 720.08, 993.60 and 405.34 is: 559.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.08 : 993.60 = 405.34 : x
  2. Step 2: Convert to fraction form
    720.08/993.60 = 405.34/x
  3. Step 3: Cross multiply
    720.08x = 993.60 × 405.34
  4. Step 4: Simplify right side
    720.08x = 402,745.82
  5. Step 5: Solve for x
    x = 402,745.82/720.08
  6. Step 6: Final answer
    x = 559.31

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.