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Finding the Fourth Proportional to 431.73, 647.78 and 258.75

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Solution

The fourth proportional to 431.73, 647.78 and 258.75 is: 388.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.73 : 647.78 = 258.75 : x
  2. Step 2: Convert to fraction form
    431.73/647.78 = 258.75/x
  3. Step 3: Cross multiply
    431.73x = 647.78 × 258.75
  4. Step 4: Simplify right side
    431.73x = 167,611.78
  5. Step 5: Solve for x
    x = 167,611.78/431.73
  6. Step 6: Final answer
    x = 388.23

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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.