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Finding the Fourth Proportional to 429.65, 643.55 and 198.20

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Solution

The fourth proportional to 429.65, 643.55 and 198.20 is: 296.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.65 : 643.55 = 198.20 : x
  2. Step 2: Convert to fraction form
    429.65/643.55 = 198.20/x
  3. Step 3: Cross multiply
    429.65x = 643.55 × 198.20
  4. Step 4: Simplify right side
    429.65x = 127,548.61
  5. Step 5: Solve for x
    x = 127,548.61/429.65
  6. Step 6: Final answer
    x = 296.86

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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.