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Finding the Fourth Proportional to 839.89, 1,258.69 and 653.39

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Solution

The fourth proportional to 839.89, 1,258.69 and 653.39 is: 979.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    839.89 : 1,258.69 = 653.39 : x
  2. Step 2: Convert to fraction form
    839.89/1,258.69 = 653.39/x
  3. Step 3: Cross multiply
    839.89x = 1,258.69 × 653.39
  4. Step 4: Simplify right side
    839.89x = 822,415.46
  5. Step 5: Solve for x
    x = 822,415.46/839.89
  6. Step 6: Final answer
    x = 979.19

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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.