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Finding the Fourth Proportional to 921.28, 1,381.88 and 401.28

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Solution

The fourth proportional to 921.28, 1,381.88 and 401.28 is: 601.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    921.28 : 1,381.88 = 401.28 : x
  2. Step 2: Convert to fraction form
    921.28/1,381.88 = 401.28/x
  3. Step 3: Cross multiply
    921.28x = 1,381.88 × 401.28
  4. Step 4: Simplify right side
    921.28x = 554,520.81
  5. Step 5: Solve for x
    x = 554,520.81/921.28
  6. Step 6: Final answer
    x = 601.90

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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.