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Finding the Fourth Proportional to 839.52, 1,258.38 and 427.80

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Solution

The fourth proportional to 839.52, 1,258.38 and 427.80 is: 641.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    839.52 : 1,258.38 = 427.80 : x
  2. Step 2: Convert to fraction form
    839.52/1,258.38 = 427.80/x
  3. Step 3: Cross multiply
    839.52x = 1,258.38 × 427.80
  4. Step 4: Simplify right side
    839.52x = 538,334.96
  5. Step 5: Solve for x
    x = 538,334.96/839.52
  6. Step 6: Final answer
    x = 641.24

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.