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Finding the Fourth Proportional to 429.25, 643.97 and 172.75

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Solution

The fourth proportional to 429.25, 643.97 and 172.75 is: 259.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.25 : 643.97 = 172.75 : x
  2. Step 2: Convert to fraction form
    429.25/643.97 = 172.75/x
  3. Step 3: Cross multiply
    429.25x = 643.97 × 172.75
  4. Step 4: Simplify right side
    429.25x = 111,245.82
  5. Step 5: Solve for x
    x = 111,245.82/429.25
  6. Step 6: Final answer
    x = 259.16

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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.