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Finding the Fourth Proportional to 1,238.85, 1,709.63 and 679.31

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Solution

The fourth proportional to 1,238.85, 1,709.63 and 679.31 is: 937.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,238.85 : 1,709.63 = 679.31 : x
  2. Step 2: Convert to fraction form
    1,238.85/1,709.63 = 679.31/x
  3. Step 3: Cross multiply
    1,238.85x = 1,709.63 × 679.31
  4. Step 4: Simplify right side
    1,238.85x = 1,161,365.36
  5. Step 5: Solve for x
    x = 1,161,365.36/1,238.85
  6. Step 6: Final answer
    x = 937.46

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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.