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Finding the Fourth Proportional to 521.99, 782.31 and 278.69

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Solution

The fourth proportional to 521.99, 782.31 and 278.69 is: 417.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.99 : 782.31 = 278.69 : x
  2. Step 2: Convert to fraction form
    521.99/782.31 = 278.69/x
  3. Step 3: Cross multiply
    521.99x = 782.31 × 278.69
  4. Step 4: Simplify right side
    521.99x = 218,021.94
  5. Step 5: Solve for x
    x = 218,021.94/521.99
  6. Step 6: Final answer
    x = 417.67

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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.