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Finding the Fourth Proportional to 720.63, 994.41 and 405.91

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Solution

The fourth proportional to 720.63, 994.41 and 405.91 is: 560.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.63 : 994.41 = 405.91 : x
  2. Step 2: Convert to fraction form
    720.63/994.41 = 405.91/x
  3. Step 3: Cross multiply
    720.63x = 994.41 × 405.91
  4. Step 4: Simplify right side
    720.63x = 403,642.21
  5. Step 5: Solve for x
    x = 403,642.21/720.63
  6. Step 6: Final answer
    x = 560.12

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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.