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Finding the Fourth Proportional to 809.64, 1,215.57 and 419.91

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Solution

The fourth proportional to 809.64, 1,215.57 and 419.91 is: 630.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.64 : 1,215.57 = 419.91 : x
  2. Step 2: Convert to fraction form
    809.64/1,215.57 = 419.91/x
  3. Step 3: Cross multiply
    809.64x = 1,215.57 × 419.91
  4. Step 4: Simplify right side
    809.64x = 510,430.00
  5. Step 5: Solve for x
    x = 510,430.00/809.64
  6. Step 6: Final answer
    x = 630.44

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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.