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Finding the Fourth Proportional to 642.81, 886.88 and 394.01

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Solution

The fourth proportional to 642.81, 886.88 and 394.01 is: 543.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.81 : 886.88 = 394.01 : x
  2. Step 2: Convert to fraction form
    642.81/886.88 = 394.01/x
  3. Step 3: Cross multiply
    642.81x = 886.88 × 394.01
  4. Step 4: Simplify right side
    642.81x = 349,439.59
  5. Step 5: Solve for x
    x = 349,439.59/642.81
  6. Step 6: Final answer
    x = 543.61

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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.