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Finding the Fourth Proportional to 811.50, 1,214.42 and 764.12

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Solution

The fourth proportional to 811.50, 1,214.42 and 764.12 is: 1,143.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.50 : 1,214.42 = 764.12 : x
  2. Step 2: Convert to fraction form
    811.50/1,214.42 = 764.12/x
  3. Step 3: Cross multiply
    811.50x = 1,214.42 × 764.12
  4. Step 4: Simplify right side
    811.50x = 927,952.72
  5. Step 5: Solve for x
    x = 927,952.72/811.50
  6. Step 6: Final answer
    x = 1,143.50

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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.