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Finding the Fourth Proportional to 809.86, 1,215.30 and 347.64

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Solution

The fourth proportional to 809.86, 1,215.30 and 347.64 is: 521.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.86 : 1,215.30 = 347.64 : x
  2. Step 2: Convert to fraction form
    809.86/1,215.30 = 347.64/x
  3. Step 3: Cross multiply
    809.86x = 1,215.30 × 347.64
  4. Step 4: Simplify right side
    809.86x = 422,486.89
  5. Step 5: Solve for x
    x = 422,486.89/809.86
  6. Step 6: Final answer
    x = 521.68

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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.