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Finding the Third Proportional to 215 and 258.50

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Solution

The third proportional to 215 and 258.50 is: 310.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    215 : 258.50 = 258.50 : x
  2. Step 2: Convert to fraction form
    215/258.50 = 258.50/x
  3. Step 3: Cross multiply
    215x = 258.50 × 258.50
  4. Step 4: Simplify right side
    215x = 66,822.25
  5. Step 5: Solve for x
    x = 66,822.25/215
  6. Step 6: Final answer
    x = 310.80

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Why These Related Problems?

These problems maintain the same ratio (1.20) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.