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Finding the Fourth Proportional to 2,129, 2,938.30 and 1,245.40

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Solution

The fourth proportional to 2,129, 2,938.30 and 1,245.40 is: 1,718.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    2,129 : 2,938.30 = 1,245.40 : x
  2. Step 2: Convert to fraction form
    2,129/2,938.30 = 1,245.40/x
  3. Step 3: Cross multiply
    2,129x = 2,938.30 × 1,245.40
  4. Step 4: Simplify right side
    2,129x = 3,659,358.82
  5. Step 5: Solve for x
    x = 3,659,358.82/2,129
  6. Step 6: Final answer
    x = 1,718.82

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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.