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Finding the Third Proportional to 308.81 and 642.94

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Solution

The third proportional to 308.81 and 642.94 is: 1,338.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    308.81 : 642.94 = 642.94 : x
  2. Step 2: Convert to fraction form
    308.81/642.94 = 642.94/x
  3. Step 3: Cross multiply
    308.81x = 642.94 × 642.94
  4. Step 4: Simplify right side
    308.81x = 413,368.63
  5. Step 5: Solve for x
    x = 413,368.63/308.81
  6. Step 6: Final answer
    x = 1,338.57

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Why These Related Problems?

These problems maintain the same ratio (2.08) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.