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Finding the Fourth Proportional to 1,422.80, 2,134.73 and 642.57

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Solution

The fourth proportional to 1,422.80, 2,134.73 and 642.57 is: 964.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,422.80 : 2,134.73 = 642.57 : x
  2. Step 2: Convert to fraction form
    1,422.80/2,134.73 = 642.57/x
  3. Step 3: Cross multiply
    1,422.80x = 2,134.73 × 642.57
  4. Step 4: Simplify right side
    1,422.80x = 1,371,713.46
  5. Step 5: Solve for x
    x = 1,371,713.46/1,422.80
  6. Step 6: Final answer
    x = 964.09

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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.