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Finding the Fourth Proportional to 810.84, 1,215.84 and 323.64

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Solution

The fourth proportional to 810.84, 1,215.84 and 323.64 is: 485.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.84 : 1,215.84 = 323.64 : x
  2. Step 2: Convert to fraction form
    810.84/1,215.84 = 323.64/x
  3. Step 3: Cross multiply
    810.84x = 1,215.84 × 323.64
  4. Step 4: Simplify right side
    810.84x = 393,494.46
  5. Step 5: Solve for x
    x = 393,494.46/810.84
  6. Step 6: Final answer
    x = 485.29

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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.