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Finding the Fourth Proportional to 1,200.09, 1,800.14 and 420.08

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Solution

The fourth proportional to 1,200.09, 1,800.14 and 420.08 is: 630.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,200.09 : 1,800.14 = 420.08 : x
  2. Step 2: Convert to fraction form
    1,200.09/1,800.14 = 420.08/x
  3. Step 3: Cross multiply
    1,200.09x = 1,800.14 × 420.08
  4. Step 4: Simplify right side
    1,200.09x = 756,200.71
  5. Step 5: Solve for x
    x = 756,200.71/1,200.09
  6. Step 6: Final answer
    x = 630.12

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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.