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Finding the Fourth Proportional to 1,216.40, 1,824.49 and 485.78

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Solution

The fourth proportional to 1,216.40, 1,824.49 and 485.78 is: 728.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,216.40 : 1,824.49 = 485.78 : x
  2. Step 2: Convert to fraction form
    1,216.40/1,824.49 = 485.78/x
  3. Step 3: Cross multiply
    1,216.40x = 1,824.49 × 485.78
  4. Step 4: Simplify right side
    1,216.40x = 886,300.75
  5. Step 5: Solve for x
    x = 886,300.75/1,216.40
  6. Step 6: Final answer
    x = 728.63

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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.