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Finding the Fourth Proportional to 679.74, 1,019.25 and 387.15

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Solution

The fourth proportional to 679.74, 1,019.25 and 387.15 is: 580.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.74 : 1,019.25 = 387.15 : x
  2. Step 2: Convert to fraction form
    679.74/1,019.25 = 387.15/x
  3. Step 3: Cross multiply
    679.74x = 1,019.25 × 387.15
  4. Step 4: Simplify right side
    679.74x = 394,602.64
  5. Step 5: Solve for x
    x = 394,602.64/679.74
  6. Step 6: Final answer
    x = 580.52

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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.