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Finding the Fourth Proportional to 911.19, 1,253.70 and 768.90

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Solution

The fourth proportional to 911.19, 1,253.70 and 768.90 is: 1,057.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    911.19 : 1,253.70 = 768.90 : x
  2. Step 2: Convert to fraction form
    911.19/1,253.70 = 768.90/x
  3. Step 3: Cross multiply
    911.19x = 1,253.70 × 768.90
  4. Step 4: Simplify right side
    911.19x = 963,969.93
  5. Step 5: Solve for x
    x = 963,969.93/911.19
  6. Step 6: Final answer
    x = 1,057.92

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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.