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Finding the Fourth Proportional to 947.09, 1,421.49 and 485.18

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Solution

The fourth proportional to 947.09, 1,421.49 and 485.18 is: 728.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    947.09 : 1,421.49 = 485.18 : x
  2. Step 2: Convert to fraction form
    947.09/1,421.49 = 485.18/x
  3. Step 3: Cross multiply
    947.09x = 1,421.49 × 485.18
  4. Step 4: Simplify right side
    947.09x = 689,680.86
  5. Step 5: Solve for x
    x = 689,680.86/947.09
  6. Step 6: Final answer
    x = 728.21

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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.