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Finding the Fourth Proportional to 429.75, 643.40 and 275.29

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Solution

The fourth proportional to 429.75, 643.40 and 275.29 is: 412.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.75 : 643.40 = 275.29 : x
  2. Step 2: Convert to fraction form
    429.75/643.40 = 275.29/x
  3. Step 3: Cross multiply
    429.75x = 643.40 × 275.29
  4. Step 4: Simplify right side
    429.75x = 177,121.59
  5. Step 5: Solve for x
    x = 177,121.59/429.75
  6. Step 6: Final answer
    x = 412.15

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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.