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Finding the Fourth Proportional to 412.90, 620.70 and 388.60

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Solution

The fourth proportional to 412.90, 620.70 and 388.60 is: 584.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    412.90 : 620.70 = 388.60 : x
  2. Step 2: Convert to fraction form
    412.90/620.70 = 388.60/x
  3. Step 3: Cross multiply
    412.90x = 620.70 × 388.60
  4. Step 4: Simplify right side
    412.90x = 241,204.02
  5. Step 5: Solve for x
    x = 241,204.02/412.90
  6. Step 6: Final answer
    x = 584.17

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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.