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Finding the Fourth Proportional to 810.36, 1,215.78 and 347.91

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Solution

The fourth proportional to 810.36, 1,215.78 and 347.91 is: 521.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.36 : 1,215.78 = 347.91 : x
  2. Step 2: Convert to fraction form
    810.36/1,215.78 = 347.91/x
  3. Step 3: Cross multiply
    810.36x = 1,215.78 × 347.91
  4. Step 4: Simplify right side
    810.36x = 422,982.02
  5. Step 5: Solve for x
    x = 422,982.02/810.36
  6. Step 6: Final answer
    x = 521.97

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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.