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Finding the Fourth Proportional to 679.40, 1,013.97 and 613.79

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Solution

The fourth proportional to 679.40, 1,013.97 and 613.79 is: 916.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.40 : 1,013.97 = 613.79 : x
  2. Step 2: Convert to fraction form
    679.40/1,013.97 = 613.79/x
  3. Step 3: Cross multiply
    679.40x = 1,013.97 × 613.79
  4. Step 4: Simplify right side
    679.40x = 622,367.18
  5. Step 5: Solve for x
    x = 622,367.18/679.40
  6. Step 6: Final answer
    x = 916.05

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.