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Finding the Fourth Proportional to 407.40, 610.20 and 190.80

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Solution

The fourth proportional to 407.40, 610.20 and 190.80 is: 285.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    407.40 : 610.20 = 190.80 : x
  2. Step 2: Convert to fraction form
    407.40/610.20 = 190.80/x
  3. Step 3: Cross multiply
    407.40x = 610.20 × 190.80
  4. Step 4: Simplify right side
    407.40x = 116,426.16
  5. Step 5: Solve for x
    x = 116,426.16/407.40
  6. Step 6: Final answer
    x = 285.78

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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.