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Finding the Fourth Proportional to 839.89, 1,158.87 and 490.42

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Solution

The fourth proportional to 839.89, 1,158.87 and 490.42 is: 676.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    839.89 : 1,158.87 = 490.42 : x
  2. Step 2: Convert to fraction form
    839.89/1,158.87 = 490.42/x
  3. Step 3: Cross multiply
    839.89x = 1,158.87 × 490.42
  4. Step 4: Simplify right side
    839.89x = 568,333.03
  5. Step 5: Solve for x
    x = 568,333.03/839.89
  6. Step 6: Final answer
    x = 676.68

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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.