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Finding the Fourth Proportional to 390.21, 537.75 and 279.50

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Solution

The fourth proportional to 390.21, 537.75 and 279.50 is: 385.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.21 : 537.75 = 279.50 : x
  2. Step 2: Convert to fraction form
    390.21/537.75 = 279.50/x
  3. Step 3: Cross multiply
    390.21x = 537.75 × 279.50
  4. Step 4: Simplify right side
    390.21x = 150,298.44
  5. Step 5: Solve for x
    x = 150,298.44/390.21
  6. Step 6: Final answer
    x = 385.17

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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.