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Finding the Fourth Proportional to 816.50, 1,221.91 and 769.12

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Solution

The fourth proportional to 816.50, 1,221.91 and 769.12 is: 1,151.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    816.50 : 1,221.91 = 769.12 : x
  2. Step 2: Convert to fraction form
    816.50/1,221.91 = 769.12/x
  3. Step 3: Cross multiply
    816.50x = 1,221.91 × 769.12
  4. Step 4: Simplify right side
    816.50x = 939,795.42
  5. Step 5: Solve for x
    x = 939,795.42/816.50
  6. Step 6: Final answer
    x = 1,151.00

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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.