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Finding the Fourth Proportional to 812.10, 1,139.10 and 812.10

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Solution

The fourth proportional to 812.10, 1,139.10 and 812.10 is: 1,139.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.10 : 1,139.10 = 812.10 : x
  2. Step 2: Convert to fraction form
    812.10/1,139.10 = 812.10/x
  3. Step 3: Cross multiply
    812.10x = 1,139.10 × 812.10
  4. Step 4: Simplify right side
    812.10x = 925,063.11
  5. Step 5: Solve for x
    x = 925,063.11/812.10
  6. Step 6: Final answer
    x = 1,139.10

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Why These Related Problems?

These problems maintain the same ratio (1.40) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.