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Finding the Fourth Proportional to 640.34, 959.79 and 311.60

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Solution

The fourth proportional to 640.34, 959.79 and 311.60 is: 467.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.34 : 959.79 = 311.60 : x
  2. Step 2: Convert to fraction form
    640.34/959.79 = 311.60/x
  3. Step 3: Cross multiply
    640.34x = 959.79 × 311.60
  4. Step 4: Simplify right side
    640.34x = 299,072.96
  5. Step 5: Solve for x
    x = 299,072.96/640.34
  6. Step 6: Final answer
    x = 467.05

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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.