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Finding the Fourth Proportional to 621.81, 858.09 and 342

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Solution

The fourth proportional to 621.81, 858.09 and 342 is: 471.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.81 : 858.09 = 342 : x
  2. Step 2: Convert to fraction form
    621.81/858.09 = 342/x
  3. Step 3: Cross multiply
    621.81x = 858.09 × 342
  4. Step 4: Simplify right side
    621.81x = 293,466.78
  5. Step 5: Solve for x
    x = 293,466.78/621.81
  6. Step 6: Final answer
    x = 471.96

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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.