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Finding the Fourth Proportional to 521.98, 720.30 and 289.11

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Solution

The fourth proportional to 521.98, 720.30 and 289.11 is: 398.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.98 : 720.30 = 289.11 : x
  2. Step 2: Convert to fraction form
    521.98/720.30 = 289.11/x
  3. Step 3: Cross multiply
    521.98x = 720.30 × 289.11
  4. Step 4: Simplify right side
    521.98x = 208,245.93
  5. Step 5: Solve for x
    x = 208,245.93/521.98
  6. Step 6: Final answer
    x = 398.95

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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.