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Finding the Fourth Proportional to 1,238.90, 1,709.66 and 679.39

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Solution

The fourth proportional to 1,238.90, 1,709.66 and 679.39 is: 937.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,238.90 : 1,709.66 = 679.39 : x
  2. Step 2: Convert to fraction form
    1,238.90/1,709.66 = 679.39/x
  3. Step 3: Cross multiply
    1,238.90x = 1,709.66 × 679.39
  4. Step 4: Simplify right side
    1,238.90x = 1,161,523.33
  5. Step 5: Solve for x
    x = 1,161,523.33/1,238.90
  6. Step 6: Final answer
    x = 937.55

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1.5x scale

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.