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Finding the Fourth Proportional to 810, 1,215.16 and 354

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Solution

The fourth proportional to 810, 1,215.16 and 354 is: 531.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    810 : 1,215.16 = 354 : x
  2. Step 2: Convert to fraction form
    810/1,215.16 = 354/x
  3. Step 3: Cross multiply
    810x = 1,215.16 × 354
  4. Step 4: Simplify right side
    810x = 430,166.64
  5. Step 5: Solve for x
    x = 430,166.64/810
  6. Step 6: Final answer
    x = 531.07

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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.