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Finding the Fourth Proportional to 412.89, 619.20 and 259.80

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Solution

The fourth proportional to 412.89, 619.20 and 259.80 is: 389.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    412.89 : 619.20 = 259.80 : x
  2. Step 2: Convert to fraction form
    412.89/619.20 = 259.80/x
  3. Step 3: Cross multiply
    412.89x = 619.20 × 259.80
  4. Step 4: Simplify right side
    412.89x = 160,868.16
  5. Step 5: Solve for x
    x = 160,868.16/412.89
  6. Step 6: Final answer
    x = 389.62

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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.