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Finding the Fourth Proportional to 287.70, 396.91 and 203.80

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Solution

The fourth proportional to 287.70, 396.91 and 203.80 is: 281.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.70 : 396.91 = 203.80 : x
  2. Step 2: Convert to fraction form
    287.70/396.91 = 203.80/x
  3. Step 3: Cross multiply
    287.70x = 396.91 × 203.80
  4. Step 4: Simplify right side
    287.70x = 80,890.26
  5. Step 5: Solve for x
    x = 80,890.26/287.70
  6. Step 6: Final answer
    x = 281.16

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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.