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Finding the Fourth Proportional to 351.80, 485.31 and 278

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Solution

The fourth proportional to 351.80, 485.31 and 278 is: 383.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    351.80 : 485.31 = 278 : x
  2. Step 2: Convert to fraction form
    351.80/485.31 = 278/x
  3. Step 3: Cross multiply
    351.80x = 485.31 × 278
  4. Step 4: Simplify right side
    351.80x = 134,916.18
  5. Step 5: Solve for x
    x = 134,916.18/351.80
  6. Step 6: Final answer
    x = 383.50

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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.