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Finding the Fourth Proportional to 647.36, 893.28 and 398.74

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Solution

The fourth proportional to 647.36, 893.28 and 398.74 is: 550.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    647.36 : 893.28 = 398.74 : x
  2. Step 2: Convert to fraction form
    647.36/893.28 = 398.74/x
  3. Step 3: Cross multiply
    647.36x = 893.28 × 398.74
  4. Step 4: Simplify right side
    647.36x = 356,186.47
  5. Step 5: Solve for x
    x = 356,186.47/647.36
  6. Step 6: Final answer
    x = 550.21

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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.