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Finding the Fourth Proportional to 947.92, 1,420.42 and 399.80

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Solution

The fourth proportional to 947.92, 1,420.42 and 399.80 is: 599.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    947.92 : 1,420.42 = 399.80 : x
  2. Step 2: Convert to fraction form
    947.92/1,420.42 = 399.80/x
  3. Step 3: Cross multiply
    947.92x = 1,420.42 × 399.80
  4. Step 4: Simplify right side
    947.92x = 567,883.92
  5. Step 5: Solve for x
    x = 567,883.92/947.92
  6. Step 6: Final answer
    x = 599.08

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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.