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Finding the Fourth Proportional to 636.91, 955.65 and 405.74

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Solution

The fourth proportional to 636.91, 955.65 and 405.74 is: 608.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    636.91 : 955.65 = 405.74 : x
  2. Step 2: Convert to fraction form
    636.91/955.65 = 405.74/x
  3. Step 3: Cross multiply
    636.91x = 955.65 × 405.74
  4. Step 4: Simplify right side
    636.91x = 387,745.43
  5. Step 5: Solve for x
    x = 387,745.43/636.91
  6. Step 6: Final answer
    x = 608.79

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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.