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Finding the Fourth Proportional to 911.70, 1,366.61 and 391.28

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Solution

The fourth proportional to 911.70, 1,366.61 and 391.28 is: 586.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    911.70 : 1,366.61 = 391.28 : x
  2. Step 2: Convert to fraction form
    911.70/1,366.61 = 391.28/x
  3. Step 3: Cross multiply
    911.70x = 1,366.61 × 391.28
  4. Step 4: Simplify right side
    911.70x = 534,718.37
  5. Step 5: Solve for x
    x = 534,718.37/911.70
  6. Step 6: Final answer
    x = 586.51

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Double scale
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1.5x scale

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.