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Finding the Fourth Proportional to 815.10, 1,222.74 and 419.94

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Solution

The fourth proportional to 815.10, 1,222.74 and 419.94 is: 629.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.10 : 1,222.74 = 419.94 : x
  2. Step 2: Convert to fraction form
    815.10/1,222.74 = 419.94/x
  3. Step 3: Cross multiply
    815.10x = 1,222.74 × 419.94
  4. Step 4: Simplify right side
    815.10x = 513,477.44
  5. Step 5: Solve for x
    x = 513,477.44/815.10
  6. Step 6: Final answer
    x = 629.96

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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.