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Finding the Fourth Proportional to 289.78, 398.86 and 250.90

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Solution

The fourth proportional to 289.78, 398.86 and 250.90 is: 345.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.78 : 398.86 = 250.90 : x
  2. Step 2: Convert to fraction form
    289.78/398.86 = 250.90/x
  3. Step 3: Cross multiply
    289.78x = 398.86 × 250.90
  4. Step 4: Simplify right side
    289.78x = 100,072.35
  5. Step 5: Solve for x
    x = 100,072.35/289.78
  6. Step 6: Final answer
    x = 345.34

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.