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Finding the Fourth Proportional to 812.25, 1,120.23 and 688.23

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Solution

The fourth proportional to 812.25, 1,120.23 and 688.23 is: 949.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.25 : 1,120.23 = 688.23 : x
  2. Step 2: Convert to fraction form
    812.25/1,120.23 = 688.23/x
  3. Step 3: Cross multiply
    812.25x = 1,120.23 × 688.23
  4. Step 4: Simplify right side
    812.25x = 770,975.89
  5. Step 5: Solve for x
    x = 770,975.89/812.25
  6. Step 6: Final answer
    x = 949.19

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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.