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Finding the Fourth Proportional to 839.64, 1,157.48 and 640.46

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Solution

The fourth proportional to 839.64, 1,157.48 and 640.46 is: 882.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    839.64 : 1,157.48 = 640.46 : x
  2. Step 2: Convert to fraction form
    839.64/1,157.48 = 640.46/x
  3. Step 3: Cross multiply
    839.64x = 1,157.48 × 640.46
  4. Step 4: Simplify right side
    839.64x = 741,319.64
  5. Step 5: Solve for x
    x = 741,319.64/839.64
  6. Step 6: Final answer
    x = 882.90

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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.