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Finding the Fourth Proportional to 643.54, 887.95 and 407.06

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Solution

The fourth proportional to 643.54, 887.95 and 407.06 is: 561.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.54 : 887.95 = 407.06 : x
  2. Step 2: Convert to fraction form
    643.54/887.95 = 407.06/x
  3. Step 3: Cross multiply
    643.54x = 887.95 × 407.06
  4. Step 4: Simplify right side
    643.54x = 361,450.13
  5. Step 5: Solve for x
    x = 361,450.13/643.54
  6. Step 6: Final answer
    x = 561.66

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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.