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Finding the Fourth Proportional to 287.78, 397.17 and 189.98

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Solution

The fourth proportional to 287.78, 397.17 and 189.98 is: 262.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.78 : 397.17 = 189.98 : x
  2. Step 2: Convert to fraction form
    287.78/397.17 = 189.98/x
  3. Step 3: Cross multiply
    287.78x = 397.17 × 189.98
  4. Step 4: Simplify right side
    287.78x = 75,454.36
  5. Step 5: Solve for x
    x = 75,454.36/287.78
  6. Step 6: Final answer
    x = 262.19

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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.