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Finding the Fourth Proportional to 1,238.33, 1,708.87 and 678.79

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Solution

The fourth proportional to 1,238.33, 1,708.87 and 678.79 is: 936.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,238.33 : 1,708.87 = 678.79 : x
  2. Step 2: Convert to fraction form
    1,238.33/1,708.87 = 678.79/x
  3. Step 3: Cross multiply
    1,238.33x = 1,708.87 × 678.79
  4. Step 4: Simplify right side
    1,238.33x = 1,159,963.87
  5. Step 5: Solve for x
    x = 1,159,963.87/1,238.33
  6. Step 6: Final answer
    x = 936.72

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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.