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Finding the Fourth Proportional to 1,239.38, 1,710.35 and 679.90

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Solution

The fourth proportional to 1,239.38, 1,710.35 and 679.90 is: 938.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,239.38 : 1,710.35 = 679.90 : x
  2. Step 2: Convert to fraction form
    1,239.38/1,710.35 = 679.90/x
  3. Step 3: Cross multiply
    1,239.38x = 1,710.35 × 679.90
  4. Step 4: Simplify right side
    1,239.38x = 1,162,855.01
  5. Step 5: Solve for x
    x = 1,162,855.01/1,239.38
  6. Step 6: Final answer
    x = 938.26

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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.