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Finding the Fourth Proportional to 389.28, 583.92 and 100.72

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Solution

The fourth proportional to 389.28, 583.92 and 100.72 is: 151.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.28 : 583.92 = 100.72 : x
  2. Step 2: Convert to fraction form
    389.28/583.92 = 100.72/x
  3. Step 3: Cross multiply
    389.28x = 583.92 × 100.72
  4. Step 4: Simplify right side
    389.28x = 58,812.42
  5. Step 5: Solve for x
    x = 58,812.42/389.28
  6. Step 6: Final answer
    x = 151.08

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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.