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Finding the Fourth Proportional to 390.20, 537.74 and 279.48

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Solution

The fourth proportional to 390.20, 537.74 and 279.48 is: 385.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.20 : 537.74 = 279.48 : x
  2. Step 2: Convert to fraction form
    390.20/537.74 = 279.48/x
  3. Step 3: Cross multiply
    390.20x = 537.74 × 279.48
  4. Step 4: Simplify right side
    390.20x = 150,289.24
  5. Step 5: Solve for x
    x = 150,289.24/390.20
  6. Step 6: Final answer
    x = 385.16

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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.