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Finding the Fourth Proportional to 809.32, 1,214.60 and 419.65

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Solution

The fourth proportional to 809.32, 1,214.60 and 419.65 is: 629.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.32 : 1,214.60 = 419.65 : x
  2. Step 2: Convert to fraction form
    809.32/1,214.60 = 419.65/x
  3. Step 3: Cross multiply
    809.32x = 1,214.60 × 419.65
  4. Step 4: Simplify right side
    809.32x = 509,706.89
  5. Step 5: Solve for x
    x = 509,706.89/809.32
  6. Step 6: Final answer
    x = 629.80

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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.