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Finding the Fourth Proportional to 628.80, 940.80 and 412.80

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Solution

The fourth proportional to 628.80, 940.80 and 412.80 is: 617.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    628.80 : 940.80 = 412.80 : x
  2. Step 2: Convert to fraction form
    628.80/940.80 = 412.80/x
  3. Step 3: Cross multiply
    628.80x = 940.80 × 412.80
  4. Step 4: Simplify right side
    628.80x = 388,362.24
  5. Step 5: Solve for x
    x = 388,362.24/628.80
  6. Step 6: Final answer
    x = 617.62

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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.