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Finding the Fourth Proportional to 1,200.50, 1,800.74 and 420.29

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Solution

The fourth proportional to 1,200.50, 1,800.74 and 420.29 is: 630.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,200.50 : 1,800.74 = 420.29 : x
  2. Step 2: Convert to fraction form
    1,200.50/1,800.74 = 420.29/x
  3. Step 3: Cross multiply
    1,200.50x = 1,800.74 × 420.29
  4. Step 4: Simplify right side
    1,200.50x = 756,833.01
  5. Step 5: Solve for x
    x = 756,833.01/1,200.50
  6. Step 6: Final answer
    x = 630.43

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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.