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Finding the Fourth Proportional to 521.61, 719.77 and 311.75

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Solution

The fourth proportional to 521.61, 719.77 and 311.75 is: 430.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.61 : 719.77 = 311.75 : x
  2. Step 2: Convert to fraction form
    521.61/719.77 = 311.75/x
  3. Step 3: Cross multiply
    521.61x = 719.77 × 311.75
  4. Step 4: Simplify right side
    521.61x = 224,385.67
  5. Step 5: Solve for x
    x = 224,385.67/521.61
  6. Step 6: Final answer
    x = 430.18

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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.