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Finding the Fourth Proportional to 429.05, 643.59 and 120.94

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Solution

The fourth proportional to 429.05, 643.59 and 120.94 is: 181.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.05 : 643.59 = 120.94 : x
  2. Step 2: Convert to fraction form
    429.05/643.59 = 120.94/x
  3. Step 3: Cross multiply
    429.05x = 643.59 × 120.94
  4. Step 4: Simplify right side
    429.05x = 77,834.17
  5. Step 5: Solve for x
    x = 77,834.17/429.05
  6. Step 6: Final answer
    x = 181.41

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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.