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Finding the Fourth Proportional to 641.81, 885.47 and 405.36

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Solution

The fourth proportional to 641.81, 885.47 and 405.36 is: 559.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.81 : 885.47 = 405.36 : x
  2. Step 2: Convert to fraction form
    641.81/885.47 = 405.36/x
  3. Step 3: Cross multiply
    641.81x = 885.47 × 405.36
  4. Step 4: Simplify right side
    641.81x = 358,932.09
  5. Step 5: Solve for x
    x = 358,932.09/641.81
  6. Step 6: Final answer
    x = 559.25

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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.