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Finding the Fourth Proportional to 521.90, 784.53 and 420.32

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Solution

The fourth proportional to 521.90, 784.53 and 420.32 is: 631.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.90 : 784.53 = 420.32 : x
  2. Step 2: Convert to fraction form
    521.90/784.53 = 420.32/x
  3. Step 3: Cross multiply
    521.90x = 784.53 × 420.32
  4. Step 4: Simplify right side
    521.90x = 329,749.73
  5. Step 5: Solve for x
    x = 329,749.73/521.90
  6. Step 6: Final answer
    x = 631.83

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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.