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Finding the Fourth Proportional to 815.40, 1,220.60 and 449.08

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Solution

The fourth proportional to 815.40, 1,220.60 and 449.08 is: 672.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.40 : 1,220.60 = 449.08 : x
  2. Step 2: Convert to fraction form
    815.40/1,220.60 = 449.08/x
  3. Step 3: Cross multiply
    815.40x = 1,220.60 × 449.08
  4. Step 4: Simplify right side
    815.40x = 548,147.05
  5. Step 5: Solve for x
    x = 548,147.05/815.40
  6. Step 6: Final answer
    x = 672.24

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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.