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Finding the Fourth Proportional to 645.75, 968.76 and 261

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Solution

The fourth proportional to 645.75, 968.76 and 261 is: 391.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.75 : 968.76 = 261 : x
  2. Step 2: Convert to fraction form
    645.75/968.76 = 261/x
  3. Step 3: Cross multiply
    645.75x = 968.76 × 261
  4. Step 4: Simplify right side
    645.75x = 252,846.36
  5. Step 5: Solve for x
    x = 252,846.36/645.75
  6. Step 6: Final answer
    x = 391.55

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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.