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Finding the Fourth Proportional to 786.46, 1,177.26 and 420.34

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Solution

The fourth proportional to 786.46, 1,177.26 and 420.34 is: 629.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    786.46 : 1,177.26 = 420.34 : x
  2. Step 2: Convert to fraction form
    786.46/1,177.26 = 420.34/x
  3. Step 3: Cross multiply
    786.46x = 1,177.26 × 420.34
  4. Step 4: Simplify right side
    786.46x = 494,849.47
  5. Step 5: Solve for x
    x = 494,849.47/786.46
  6. Step 6: Final answer
    x = 629.21

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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.