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Finding the Fourth Proportional to 764.20, 1,146.30 and 659.80

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Solution

The fourth proportional to 764.20, 1,146.30 and 659.80 is: 989.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    764.20 : 1,146.30 = 659.80 : x
  2. Step 2: Convert to fraction form
    764.20/1,146.30 = 659.80/x
  3. Step 3: Cross multiply
    764.20x = 1,146.30 × 659.80
  4. Step 4: Simplify right side
    764.20x = 756,328.74
  5. Step 5: Solve for x
    x = 756,328.74/764.20
  6. Step 6: Final answer
    x = 989.70

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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.