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Finding the Fourth Proportional to 809.42, 1,215.24 and 419.74

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Solution

The fourth proportional to 809.42, 1,215.24 and 419.74 is: 630.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.42 : 1,215.24 = 419.74 : x
  2. Step 2: Convert to fraction form
    809.42/1,215.24 = 419.74/x
  3. Step 3: Cross multiply
    809.42x = 1,215.24 × 419.74
  4. Step 4: Simplify right side
    809.42x = 510,084.84
  5. Step 5: Solve for x
    x = 510,084.84/809.42
  6. Step 6: Final answer
    x = 630.19

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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.