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Finding the Fourth Proportional to 521.80, 782.70 and 305.80

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Solution

The fourth proportional to 521.80, 782.70 and 305.80 is: 458.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.80 : 782.70 = 305.80 : x
  2. Step 2: Convert to fraction form
    521.80/782.70 = 305.80/x
  3. Step 3: Cross multiply
    521.80x = 782.70 × 305.80
  4. Step 4: Simplify right side
    521.80x = 239,349.66
  5. Step 5: Solve for x
    x = 239,349.66/521.80
  6. Step 6: Final answer
    x = 458.70

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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.