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Finding the Fourth Proportional to 879.78, 1,213.99 and 486.81

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Solution

The fourth proportional to 879.78, 1,213.99 and 486.81 is: 671.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    879.78 : 1,213.99 = 486.81 : x
  2. Step 2: Convert to fraction form
    879.78/1,213.99 = 486.81/x
  3. Step 3: Cross multiply
    879.78x = 1,213.99 × 486.81
  4. Step 4: Simplify right side
    879.78x = 590,982.47
  5. Step 5: Solve for x
    x = 590,982.47/879.78
  6. Step 6: Final answer
    x = 671.74

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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.