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Finding the Fourth Proportional to 763.86, 1,145.79 and 330.78

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Solution

The fourth proportional to 763.86, 1,145.79 and 330.78 is: 496.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    763.86 : 1,145.79 = 330.78 : x
  2. Step 2: Convert to fraction form
    763.86/1,145.79 = 330.78/x
  3. Step 3: Cross multiply
    763.86x = 1,145.79 × 330.78
  4. Step 4: Simplify right side
    763.86x = 379,004.42
  5. Step 5: Solve for x
    x = 379,004.42/763.86
  6. Step 6: Final answer
    x = 496.17

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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.