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Finding the Fourth Proportional to 640.74, 960.99 and 207.78

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Solution

The fourth proportional to 640.74, 960.99 and 207.78 is: 311.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.74 : 960.99 = 207.78 : x
  2. Step 2: Convert to fraction form
    640.74/960.99 = 207.78/x
  3. Step 3: Cross multiply
    640.74x = 960.99 × 207.78
  4. Step 4: Simplify right side
    640.74x = 199,674.50
  5. Step 5: Solve for x
    x = 199,674.50/640.74
  6. Step 6: Final answer
    x = 311.63

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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.