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Finding the Third Proportional to 278 and 621.50

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Solution

The third proportional to 278 and 621.50 is: 1,389.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    278 : 621.50 = 621.50 : x
  2. Step 2: Convert to fraction form
    278/621.50 = 621.50/x
  3. Step 3: Cross multiply
    278x = 621.50 × 621.50
  4. Step 4: Simplify right side
    278x = 386,262.25
  5. Step 5: Solve for x
    x = 386,262.25/278
  6. Step 6: Final answer
    x = 1,389.43

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Why These Related Problems?

These problems maintain the same ratio (2.24) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.