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Finding the Fourth Proportional to 771.21, 1,156.20 and 338.13

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Solution

The fourth proportional to 771.21, 1,156.20 and 338.13 is: 506.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    771.21 : 1,156.20 = 338.13 : x
  2. Step 2: Convert to fraction form
    771.21/1,156.20 = 338.13/x
  3. Step 3: Cross multiply
    771.21x = 1,156.20 × 338.13
  4. Step 4: Simplify right side
    771.21x = 390,945.91
  5. Step 5: Solve for x
    x = 390,945.91/771.21
  6. Step 6: Final answer
    x = 506.93

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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.