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Finding the Third Proportional to 216 and 391.50

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Solution

The third proportional to 216 and 391.50 is: 709.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    216 : 391.50 = 391.50 : x
  2. Step 2: Convert to fraction form
    216/391.50 = 391.50/x
  3. Step 3: Cross multiply
    216x = 391.50 × 391.50
  4. Step 4: Simplify right side
    216x = 153,272.25
  5. Step 5: Solve for x
    x = 153,272.25/216
  6. Step 6: Final answer
    x = 709.59

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Why These Related Problems?

These problems maintain the same ratio (1.81) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.