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Finding the Fourth Proportional to 389.80, 538.14 and 305.83

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Solution

The fourth proportional to 389.80, 538.14 and 305.83 is: 422.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.80 : 538.14 = 305.83 : x
  2. Step 2: Convert to fraction form
    389.80/538.14 = 305.83/x
  3. Step 3: Cross multiply
    389.80x = 538.14 × 305.83
  4. Step 4: Simplify right side
    389.80x = 164,579.36
  5. Step 5: Solve for x
    x = 164,579.36/389.80
  6. Step 6: Final answer
    x = 422.21

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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.