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Finding the Third Proportional to 285 and 420.38

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Solution

The third proportional to 285 and 420.38 is: 620.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    285 : 420.38 = 420.38 : x
  2. Step 2: Convert to fraction form
    285/420.38 = 420.38/x
  3. Step 3: Cross multiply
    285x = 420.38 × 420.38
  4. Step 4: Simplify right side
    285x = 176,715.14
  5. Step 5: Solve for x
    x = 176,715.14/285
  6. Step 6: Final answer
    x = 620.05

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Why These Related Problems?

These problems maintain the same ratio (1.48) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.