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Finding the Fourth Proportional to 815.50, 1,222.64 and 490.79

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Solution

The fourth proportional to 815.50, 1,222.64 and 490.79 is: 735.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.50 : 1,222.64 = 490.79 : x
  2. Step 2: Convert to fraction form
    815.50/1,222.64 = 490.79/x
  3. Step 3: Cross multiply
    815.50x = 1,222.64 × 490.79
  4. Step 4: Simplify right side
    815.50x = 600,064.69
  5. Step 5: Solve for x
    x = 600,064.69/815.50
  6. Step 6: Final answer
    x = 735.82

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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.