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Finding the Fourth Proportional to 521.08, 718.96 and 311.28

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Solution

The fourth proportional to 521.08, 718.96 and 311.28 is: 429.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.08 : 718.96 = 311.28 : x
  2. Step 2: Convert to fraction form
    521.08/718.96 = 311.28/x
  3. Step 3: Cross multiply
    521.08x = 718.96 × 311.28
  4. Step 4: Simplify right side
    521.08x = 223,797.87
  5. Step 5: Solve for x
    x = 223,797.87/521.08
  6. Step 6: Final answer
    x = 429.49

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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.