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Finding the Fourth Proportional to 818.10, 1,225.80 and 680.40

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Solution

The fourth proportional to 818.10, 1,225.80 and 680.40 is: 1,019.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.10 : 1,225.80 = 680.40 : x
  2. Step 2: Convert to fraction form
    818.10/1,225.80 = 680.40/x
  3. Step 3: Cross multiply
    818.10x = 1,225.80 × 680.40
  4. Step 4: Simplify right side
    818.10x = 834,034.32
  5. Step 5: Solve for x
    x = 834,034.32/818.10
  6. Step 6: Final answer
    x = 1,019.48

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.