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Finding the Fourth Proportional to 1,239.10, 1,709.89 and 679.53

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Solution

The fourth proportional to 1,239.10, 1,709.89 and 679.53 is: 937.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,239.10 : 1,709.89 = 679.53 : x
  2. Step 2: Convert to fraction form
    1,239.10/1,709.89 = 679.53/x
  3. Step 3: Cross multiply
    1,239.10x = 1,709.89 × 679.53
  4. Step 4: Simplify right side
    1,239.10x = 1,161,926.26
  5. Step 5: Solve for x
    x = 1,161,926.26/1,239.10
  6. Step 6: Final answer
    x = 937.72

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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.