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Finding the Fourth Proportional to 879.12, 1,213.28 and 657.70

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Solution

The fourth proportional to 879.12, 1,213.28 and 657.70 is: 907.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    879.12 : 1,213.28 = 657.70 : x
  2. Step 2: Convert to fraction form
    879.12/1,213.28 = 657.70/x
  3. Step 3: Cross multiply
    879.12x = 1,213.28 × 657.70
  4. Step 4: Simplify right side
    879.12x = 797,974.26
  5. Step 5: Solve for x
    x = 797,974.26/879.12
  6. Step 6: Final answer
    x = 907.70

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.