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Finding the Fourth Proportional to 286.40, 394.40 and 280.36

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Solution

The fourth proportional to 286.40, 394.40 and 280.36 is: 386.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    286.40 : 394.40 = 280.36 : x
  2. Step 2: Convert to fraction form
    286.40/394.40 = 280.36/x
  3. Step 3: Cross multiply
    286.40x = 394.40 × 280.36
  4. Step 4: Simplify right side
    286.40x = 110,573.98
  5. Step 5: Solve for x
    x = 110,573.98/286.40
  6. Step 6: Final answer
    x = 386.08

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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.