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Finding the Fourth Proportional to 309.82, 427.68 and 280.18

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Solution

The fourth proportional to 309.82, 427.68 and 280.18 is: 386.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.82 : 427.68 = 280.18 : x
  2. Step 2: Convert to fraction form
    309.82/427.68 = 280.18/x
  3. Step 3: Cross multiply
    309.82x = 427.68 × 280.18
  4. Step 4: Simplify right side
    309.82x = 119,827.38
  5. Step 5: Solve for x
    x = 119,827.38/309.82
  6. Step 6: Final answer
    x = 386.76

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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.