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Finding the Fourth Proportional to 643, 886.86 and 407.08

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Solution

The fourth proportional to 643, 886.86 and 407.08 is: 561.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    643 : 886.86 = 407.08 : x
  2. Step 2: Convert to fraction form
    643/886.86 = 407.08/x
  3. Step 3: Cross multiply
    643x = 886.86 × 407.08
  4. Step 4: Simplify right side
    643x = 361,022.97
  5. Step 5: Solve for x
    x = 361,022.97/643
  6. Step 6: Final answer
    x = 561.47

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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.