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Finding the Fourth Proportional to 640.75, 961.40 and 347.91

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Solution

The fourth proportional to 640.75, 961.40 and 347.91 is: 522.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.75 : 961.40 = 347.91 : x
  2. Step 2: Convert to fraction form
    640.75/961.40 = 347.91/x
  3. Step 3: Cross multiply
    640.75x = 961.40 × 347.91
  4. Step 4: Simplify right side
    640.75x = 334,480.67
  5. Step 5: Solve for x
    x = 334,480.67/640.75
  6. Step 6: Final answer
    x = 522.01

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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.