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Finding the Fourth Proportional to 947.09, 1,420.43 and 399.12

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Solution

The fourth proportional to 947.09, 1,420.43 and 399.12 is: 598.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    947.09 : 1,420.43 = 399.12 : x
  2. Step 2: Convert to fraction form
    947.09/1,420.43 = 399.12/x
  3. Step 3: Cross multiply
    947.09x = 1,420.43 × 399.12
  4. Step 4: Simplify right side
    947.09x = 566,920.03
  5. Step 5: Solve for x
    x = 566,920.03/947.09
  6. Step 6: Final answer
    x = 598.59

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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.