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Finding the Fourth Proportional to 645.64, 891.30 and 449.32

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Solution

The fourth proportional to 645.64, 891.30 and 449.32 is: 620.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.64 : 891.30 = 449.32 : x
  2. Step 2: Convert to fraction form
    645.64/891.30 = 449.32/x
  3. Step 3: Cross multiply
    645.64x = 891.30 × 449.32
  4. Step 4: Simplify right side
    645.64x = 400,478.92
  5. Step 5: Solve for x
    x = 400,478.92/645.64
  6. Step 6: Final answer
    x = 620.28

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.