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Finding the Fourth Proportional to 2,102.72, 3,153.90 and 642.20

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Solution

The fourth proportional to 2,102.72, 3,153.90 and 642.20 is: 963.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    2,102.72 : 3,153.90 = 642.20 : x
  2. Step 2: Convert to fraction form
    2,102.72/3,153.90 = 642.20/x
  3. Step 3: Cross multiply
    2,102.72x = 3,153.90 × 642.20
  4. Step 4: Simplify right side
    2,102.72x = 2,025,434.58
  5. Step 5: Solve for x
    x = 2,025,434.58/2,102.72
  6. Step 6: Final answer
    x = 963.25

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.