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Finding the Fourth Proportional to 820.28, 1,223.69 and 761.36

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Solution

The fourth proportional to 820.28, 1,223.69 and 761.36 is: 1,135.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.28 : 1,223.69 = 761.36 : x
  2. Step 2: Convert to fraction form
    820.28/1,223.69 = 761.36/x
  3. Step 3: Cross multiply
    820.28x = 1,223.69 × 761.36
  4. Step 4: Simplify right side
    820.28x = 931,658.69
  5. Step 5: Solve for x
    x = 931,658.69/820.28
  6. Step 6: Final answer
    x = 1,135.78

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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.