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Finding the Third Proportional to 209 and 316.25

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Solution

The third proportional to 209 and 316.25 is: 478.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    209 : 316.25 = 316.25 : x
  2. Step 2: Convert to fraction form
    209/316.25 = 316.25/x
  3. Step 3: Cross multiply
    209x = 316.25 × 316.25
  4. Step 4: Simplify right side
    209x = 100,014.06
  5. Step 5: Solve for x
    x = 100,014.06/209
  6. Step 6: Final answer
    x = 478.54

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.