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Finding the Fourth Proportional to 720.45, 994.21 and 421.91

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Solution

The fourth proportional to 720.45, 994.21 and 421.91 is: 582.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.45 : 994.21 = 421.91 : x
  2. Step 2: Convert to fraction form
    720.45/994.21 = 421.91/x
  3. Step 3: Cross multiply
    720.45x = 994.21 × 421.91
  4. Step 4: Simplify right side
    720.45x = 419,462.70
  5. Step 5: Solve for x
    x = 419,462.70/720.45
  6. Step 6: Final answer
    x = 582.22

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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.