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Finding the Fourth Proportional to 1,381.70, 1,906.80 and 909.74

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Solution

The fourth proportional to 1,381.70, 1,906.80 and 909.74 is: 1,255.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,381.70 : 1,906.80 = 909.74 : x
  2. Step 2: Convert to fraction form
    1,381.70/1,906.80 = 909.74/x
  3. Step 3: Cross multiply
    1,381.70x = 1,906.80 × 909.74
  4. Step 4: Simplify right side
    1,381.70x = 1,734,692.23
  5. Step 5: Solve for x
    x = 1,734,692.23/1,381.70
  6. Step 6: Final answer
    x = 1,255.48

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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.