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Finding the Fourth Proportional to 420.79, 580.72 and 243.81

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Solution

The fourth proportional to 420.79, 580.72 and 243.81 is: 336.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.79 : 580.72 = 243.81 : x
  2. Step 2: Convert to fraction form
    420.79/580.72 = 243.81/x
  3. Step 3: Cross multiply
    420.79x = 580.72 × 243.81
  4. Step 4: Simplify right side
    420.79x = 141,585.34
  5. Step 5: Solve for x
    x = 141,585.34/420.79
  6. Step 6: Final answer
    x = 336.48

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.