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Finding the Fourth Proportional to 857.38, 1,183.86 and 638.68

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Solution

The fourth proportional to 857.38, 1,183.86 and 638.68 is: 881.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.38 : 1,183.86 = 638.68 : x
  2. Step 2: Convert to fraction form
    857.38/1,183.86 = 638.68/x
  3. Step 3: Cross multiply
    857.38x = 1,183.86 × 638.68
  4. Step 4: Simplify right side
    857.38x = 756,107.70
  5. Step 5: Solve for x
    x = 756,107.70/857.38
  6. Step 6: Final answer
    x = 881.88

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Double scale
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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.