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Finding the Fourth Proportional to 679.41, 930.56 and 639.51

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Solution

The fourth proportional to 679.41, 930.56 and 639.51 is: 875.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.41 : 930.56 = 639.51 : x
  2. Step 2: Convert to fraction form
    679.41/930.56 = 639.51/x
  3. Step 3: Cross multiply
    679.41x = 930.56 × 639.51
  4. Step 4: Simplify right side
    679.41x = 595,099.89
  5. Step 5: Solve for x
    x = 595,099.89/679.41
  6. Step 6: Final answer
    x = 875.91

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.