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Finding the Third Proportional to 78 and 140.25

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Solution

The third proportional to 78 and 140.25 is: 252.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    78 : 140.25 = 140.25 : x
  2. Step 2: Convert to fraction form
    78/140.25 = 140.25/x
  3. Step 3: Cross multiply
    78x = 140.25 × 140.25
  4. Step 4: Simplify right side
    78x = 19,670.06
  5. Step 5: Solve for x
    x = 19,670.06/78
  6. Step 6: Final answer
    x = 252.18

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Why These Related Problems?

These problems maintain the same ratio (1.80) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.