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Finding the Fourth Proportional to 879.31, 1,213.40 and 486.31

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Solution

The fourth proportional to 879.31, 1,213.40 and 486.31 is: 671.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    879.31 : 1,213.40 = 486.31 : x
  2. Step 2: Convert to fraction form
    879.31/1,213.40 = 486.31/x
  3. Step 3: Cross multiply
    879.31x = 1,213.40 × 486.31
  4. Step 4: Simplify right side
    879.31x = 590,083.09
  5. Step 5: Solve for x
    x = 590,083.09/879.31
  6. Step 6: Final answer
    x = 671.08

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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.