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Finding the Fourth Proportional to 378.36, 521.91 and 280.35

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Solution

The fourth proportional to 378.36, 521.91 and 280.35 is: 386.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.36 : 521.91 = 280.35 : x
  2. Step 2: Convert to fraction form
    378.36/521.91 = 280.35/x
  3. Step 3: Cross multiply
    378.36x = 521.91 × 280.35
  4. Step 4: Simplify right side
    378.36x = 146,317.47
  5. Step 5: Solve for x
    x = 146,317.47/378.36
  6. Step 6: Final answer
    x = 386.71

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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.