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Finding the Third Proportional to 399 and 624.75

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Solution

The third proportional to 399 and 624.75 is: 978.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    399 : 624.75 = 624.75 : x
  2. Step 2: Convert to fraction form
    399/624.75 = 624.75/x
  3. Step 3: Cross multiply
    399x = 624.75 × 624.75
  4. Step 4: Simplify right side
    399x = 390,312.56
  5. Step 5: Solve for x
    x = 390,312.56/399
  6. Step 6: Final answer
    x = 978.23

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Why These Related Problems?

These problems maintain the same ratio (1.57) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.