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Finding the Fourth Proportional to 521.65, 720.87 and 428.23

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Solution

The fourth proportional to 521.65, 720.87 and 428.23 is: 591.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.65 : 720.87 = 428.23 : x
  2. Step 2: Convert to fraction form
    521.65/720.87 = 428.23/x
  3. Step 3: Cross multiply
    521.65x = 720.87 × 428.23
  4. Step 4: Simplify right side
    521.65x = 308,698.16
  5. Step 5: Solve for x
    x = 308,698.16/521.65
  6. Step 6: Final answer
    x = 591.77

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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.