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Finding the Fourth Proportional to 720.11, 993.65 and 405.32

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Solution

The fourth proportional to 720.11, 993.65 and 405.32 is: 559.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.11 : 993.65 = 405.32 : x
  2. Step 2: Convert to fraction form
    720.11/993.65 = 405.32/x
  3. Step 3: Cross multiply
    720.11x = 993.65 × 405.32
  4. Step 4: Simplify right side
    720.11x = 402,739.22
  5. Step 5: Solve for x
    x = 402,739.22/720.11
  6. Step 6: Final answer
    x = 559.28

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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.