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Finding the Fourth Proportional to 670.75, 1,005.51 and 396.78

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Solution

The fourth proportional to 670.75, 1,005.51 and 396.78 is: 594.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    670.75 : 1,005.51 = 396.78 : x
  2. Step 2: Convert to fraction form
    670.75/1,005.51 = 396.78/x
  3. Step 3: Cross multiply
    670.75x = 1,005.51 × 396.78
  4. Step 4: Simplify right side
    670.75x = 398,966.26
  5. Step 5: Solve for x
    x = 398,966.26/670.75
  6. Step 6: Final answer
    x = 594.81

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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.