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Finding the Fourth Proportional to 640.55, 959.90 and 347.81

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Solution

The fourth proportional to 640.55, 959.90 and 347.81 is: 521.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.55 : 959.90 = 347.81 : x
  2. Step 2: Convert to fraction form
    640.55/959.90 = 347.81/x
  3. Step 3: Cross multiply
    640.55x = 959.90 × 347.81
  4. Step 4: Simplify right side
    640.55x = 333,856.28
  5. Step 5: Solve for x
    x = 333,856.28/640.55
  6. Step 6: Final answer
    x = 521.20

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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.