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Finding the Fourth Proportional to 640.10, 957.92 and 393.20

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Solution

The fourth proportional to 640.10, 957.92 and 393.20 is: 588.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.10 : 957.92 = 393.20 : x
  2. Step 2: Convert to fraction form
    640.10/957.92 = 393.20/x
  3. Step 3: Cross multiply
    640.10x = 957.92 × 393.20
  4. Step 4: Simplify right side
    640.10x = 376,649.35
  5. Step 5: Solve for x
    x = 376,649.35/640.10
  6. Step 6: Final answer
    x = 588.42

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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.