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Finding the Fourth Proportional to 643.81, 889.37 and 512.65

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Solution

The fourth proportional to 643.81, 889.37 and 512.65 is: 708.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.81 : 889.37 = 512.65 : x
  2. Step 2: Convert to fraction form
    643.81/889.37 = 512.65/x
  3. Step 3: Cross multiply
    643.81x = 889.37 × 512.65
  4. Step 4: Simplify right side
    643.81x = 455,935.53
  5. Step 5: Solve for x
    x = 455,935.53/643.81
  6. Step 6: Final answer
    x = 708.18

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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.