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Finding the Fourth Proportional to 509.45, 763.38 and 428.45

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Solution

The fourth proportional to 509.45, 763.38 and 428.45 is: 642.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    509.45 : 763.38 = 428.45 : x
  2. Step 2: Convert to fraction form
    509.45/763.38 = 428.45/x
  3. Step 3: Cross multiply
    509.45x = 763.38 × 428.45
  4. Step 4: Simplify right side
    509.45x = 327,066.34
  5. Step 5: Solve for x
    x = 327,066.34/509.45
  6. Step 6: Final answer
    x = 642.01

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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.