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Finding the Fourth Proportional to 810.80, 1,216.20 and 225.80

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Solution

The fourth proportional to 810.80, 1,216.20 and 225.80 is: 338.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.80 : 1,216.20 = 225.80 : x
  2. Step 2: Convert to fraction form
    810.80/1,216.20 = 225.80/x
  3. Step 3: Cross multiply
    810.80x = 1,216.20 × 225.80
  4. Step 4: Simplify right side
    810.80x = 274,617.96
  5. Step 5: Solve for x
    x = 274,617.96/810.80
  6. Step 6: Final answer
    x = 338.70

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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.