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Finding the Fourth Proportional to 810.70, 1,216.50 and 323.79

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Solution

The fourth proportional to 810.70, 1,216.50 and 323.79 is: 485.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.70 : 1,216.50 = 323.79 : x
  2. Step 2: Convert to fraction form
    810.70/1,216.50 = 323.79/x
  3. Step 3: Cross multiply
    810.70x = 1,216.50 × 323.79
  4. Step 4: Simplify right side
    810.70x = 393,890.54
  5. Step 5: Solve for x
    x = 393,890.54/810.70
  6. Step 6: Final answer
    x = 485.86

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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.