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Finding the Third Proportional to 690 and 880

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Solution

The third proportional to 690 and 880 is: 1,122.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    690 : 880 = 880 : x
  2. Step 2: Convert to fraction form
    690/880 = 880/x
  3. Step 3: Cross multiply
    690x = 880 × 880
  4. Step 4: Simplify right side
    690x = 774,400
  5. Step 5: Solve for x
    x = 774,400/690
  6. Step 6: Final answer
    x = 1,122.32

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Why These Related Problems?

These problems maintain the same ratio (1.28) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.