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Finding the Fourth Proportional to 785.76, 1,179.72 and 664.80

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Solution

The fourth proportional to 785.76, 1,179.72 and 664.80 is: 998.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    785.76 : 1,179.72 = 664.80 : x
  2. Step 2: Convert to fraction form
    785.76/1,179.72 = 664.80/x
  3. Step 3: Cross multiply
    785.76x = 1,179.72 × 664.80
  4. Step 4: Simplify right side
    785.76x = 784,277.86
  5. Step 5: Solve for x
    x = 784,277.86/785.76
  6. Step 6: Final answer
    x = 998.11

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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.