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Finding the Fourth Proportional to 389.11, 537.66 and 278.40

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Solution

The fourth proportional to 389.11, 537.66 and 278.40 is: 384.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.11 : 537.66 = 278.40 : x
  2. Step 2: Convert to fraction form
    389.11/537.66 = 278.40/x
  3. Step 3: Cross multiply
    389.11x = 537.66 × 278.40
  4. Step 4: Simplify right side
    389.11x = 149,684.54
  5. Step 5: Solve for x
    x = 149,684.54/389.11
  6. Step 6: Final answer
    x = 384.68

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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.