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Finding the Fourth Proportional to 378.09, 520.70 and 280.08

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Solution

The fourth proportional to 378.09, 520.70 and 280.08 is: 385.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.09 : 520.70 = 280.08 : x
  2. Step 2: Convert to fraction form
    378.09/520.70 = 280.08/x
  3. Step 3: Cross multiply
    378.09x = 520.70 × 280.08
  4. Step 4: Simplify right side
    378.09x = 145,836.26
  5. Step 5: Solve for x
    x = 145,836.26/378.09
  6. Step 6: Final answer
    x = 385.72

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.