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Finding the Fourth Proportional to 389.19, 537.77 and 311.15

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Solution

The fourth proportional to 389.19, 537.77 and 311.15 is: 429.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.19 : 537.77 = 311.15 : x
  2. Step 2: Convert to fraction form
    389.19/537.77 = 311.15/x
  3. Step 3: Cross multiply
    389.19x = 537.77 × 311.15
  4. Step 4: Simplify right side
    389.19x = 167,330.39
  5. Step 5: Solve for x
    x = 167,330.39/389.19
  6. Step 6: Final answer
    x = 429.94

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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.