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Finding the Fourth Proportional to 521.39, 719.61 and 311.50

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Solution

The fourth proportional to 521.39, 719.61 and 311.50 is: 429.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.39 : 719.61 = 311.50 : x
  2. Step 2: Convert to fraction form
    521.39/719.61 = 311.50/x
  3. Step 3: Cross multiply
    521.39x = 719.61 × 311.50
  4. Step 4: Simplify right side
    521.39x = 224,158.52
  5. Step 5: Solve for x
    x = 224,158.52/521.39
  6. Step 6: Final answer
    x = 429.92

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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.