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Finding the Fourth Proportional to 851.20, 1,276.80 and 818.80

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Solution

The fourth proportional to 851.20, 1,276.80 and 818.80 is: 1,228.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    851.20 : 1,276.80 = 818.80 : x
  2. Step 2: Convert to fraction form
    851.20/1,276.80 = 818.80/x
  3. Step 3: Cross multiply
    851.20x = 1,276.80 × 818.80
  4. Step 4: Simplify right side
    851.20x = 1,045,443.84
  5. Step 5: Solve for x
    x = 1,045,443.84/851.20
  6. Step 6: Final answer
    x = 1,228.20

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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.