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Finding the Fourth Proportional to 403.75, 557.31 and 287.65

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Solution

The fourth proportional to 403.75, 557.31 and 287.65 is: 397.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    403.75 : 557.31 = 287.65 : x
  2. Step 2: Convert to fraction form
    403.75/557.31 = 287.65/x
  3. Step 3: Cross multiply
    403.75x = 557.31 × 287.65
  4. Step 4: Simplify right side
    403.75x = 160,310.22
  5. Step 5: Solve for x
    x = 160,310.22/403.75
  6. Step 6: Final answer
    x = 397.05

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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.