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Finding the Fourth Proportional to 906.39, 1,249.32 and 640.91

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Solution

The fourth proportional to 906.39, 1,249.32 and 640.91 is: 883.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    906.39 : 1,249.32 = 640.91 : x
  2. Step 2: Convert to fraction form
    906.39/1,249.32 = 640.91/x
  3. Step 3: Cross multiply
    906.39x = 1,249.32 × 640.91
  4. Step 4: Simplify right side
    906.39x = 800,707.21
  5. Step 5: Solve for x
    x = 800,707.21/906.39
  6. Step 6: Final answer
    x = 883.40

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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.