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Finding the Fourth Proportional to 1,238.80, 1,709.47 and 679.16

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Solution

The fourth proportional to 1,238.80, 1,709.47 and 679.16 is: 937.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,238.80 : 1,709.47 = 679.16 : x
  2. Step 2: Convert to fraction form
    1,238.80/1,709.47 = 679.16/x
  3. Step 3: Cross multiply
    1,238.80x = 1,709.47 × 679.16
  4. Step 4: Simplify right side
    1,238.80x = 1,161,003.65
  5. Step 5: Solve for x
    x = 1,161,003.65/1,238.80
  6. Step 6: Final answer
    x = 937.20

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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.