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Finding the Fourth Proportional to 815.24, 1,215.09 and 769.10

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Solution

The fourth proportional to 815.24, 1,215.09 and 769.10 is: 1,146.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.24 : 1,215.09 = 769.10 : x
  2. Step 2: Convert to fraction form
    815.24/1,215.09 = 769.10/x
  3. Step 3: Cross multiply
    815.24x = 1,215.09 × 769.10
  4. Step 4: Simplify right side
    815.24x = 934,519.64
  5. Step 5: Solve for x
    x = 934,519.64/815.24
  6. Step 6: Final answer
    x = 1,146.32

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.