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Finding the Fourth Proportional to 812.85, 1,121.70 and 481.32

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Solution

The fourth proportional to 812.85, 1,121.70 and 481.32 is: 664.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.85 : 1,121.70 = 481.32 : x
  2. Step 2: Convert to fraction form
    812.85/1,121.70 = 481.32/x
  3. Step 3: Cross multiply
    812.85x = 1,121.70 × 481.32
  4. Step 4: Simplify right side
    812.85x = 539,896.64
  5. Step 5: Solve for x
    x = 539,896.64/812.85
  6. Step 6: Final answer
    x = 664.20

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1.5x scale

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.