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Finding the Fourth Proportional to 405.80, 607.85 and 394.39

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Solution

The fourth proportional to 405.80, 607.85 and 394.39 is: 590.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.80 : 607.85 = 394.39 : x
  2. Step 2: Convert to fraction form
    405.80/607.85 = 394.39/x
  3. Step 3: Cross multiply
    405.80x = 607.85 × 394.39
  4. Step 4: Simplify right side
    405.80x = 239,729.96
  5. Step 5: Solve for x
    x = 239,729.96/405.80
  6. Step 6: Final answer
    x = 590.76

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.