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Finding the Fourth Proportional to 818.31, 1,128.90 and 486.56

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Solution

The fourth proportional to 818.31, 1,128.90 and 486.56 is: 671.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.31 : 1,128.90 = 486.56 : x
  2. Step 2: Convert to fraction form
    818.31/1,128.90 = 486.56/x
  3. Step 3: Cross multiply
    818.31x = 1,128.90 × 486.56
  4. Step 4: Simplify right side
    818.31x = 549,271.94
  5. Step 5: Solve for x
    x = 549,271.94/818.31
  6. Step 6: Final answer
    x = 671.23

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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.