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Finding the Fourth Proportional to 1,542, 2,128.20 and 921.36

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Solution

The fourth proportional to 1,542, 2,128.20 and 921.36 is: 1,271.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,542 : 2,128.20 = 921.36 : x
  2. Step 2: Convert to fraction form
    1,542/2,128.20 = 921.36/x
  3. Step 3: Cross multiply
    1,542x = 2,128.20 × 921.36
  4. Step 4: Simplify right side
    1,542x = 1,960,838.35
  5. Step 5: Solve for x
    x = 1,960,838.35/1,542
  6. Step 6: Final answer
    x = 1,271.62

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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.