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Finding the Fourth Proportional to 643.91, 889.76 and 513.95

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Solution

The fourth proportional to 643.91, 889.76 and 513.95 is: 710.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.91 : 889.76 = 513.95 : x
  2. Step 2: Convert to fraction form
    643.91/889.76 = 513.95/x
  3. Step 3: Cross multiply
    643.91x = 889.76 × 513.95
  4. Step 4: Simplify right side
    643.91x = 457,289.58
  5. Step 5: Solve for x
    x = 457,289.58/643.91
  6. Step 6: Final answer
    x = 710.18

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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.