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Finding the Fourth Proportional to 621.81, 857.79 and 538.79

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Solution

The fourth proportional to 621.81, 857.79 and 538.79 is: 743.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.81 : 857.79 = 538.79 : x
  2. Step 2: Convert to fraction form
    621.81/857.79 = 538.79/x
  3. Step 3: Cross multiply
    621.81x = 857.79 × 538.79
  4. Step 4: Simplify right side
    621.81x = 462,164.39
  5. Step 5: Solve for x
    x = 462,164.39/621.81
  6. Step 6: Final answer
    x = 743.26

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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.