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Finding the Fourth Proportional to 818.30, 1,129.31 and 486.74

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Solution

The fourth proportional to 818.30, 1,129.31 and 486.74 is: 671.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.30 : 1,129.31 = 486.74 : x
  2. Step 2: Convert to fraction form
    818.30/1,129.31 = 486.74/x
  3. Step 3: Cross multiply
    818.30x = 1,129.31 × 486.74
  4. Step 4: Simplify right side
    818.30x = 549,682.56
  5. Step 5: Solve for x
    x = 549,682.56/818.30
  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.