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Finding the Fourth Proportional to 642.15, 886.31 and 455.95

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Solution

The fourth proportional to 642.15, 886.31 and 455.95 is: 629.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.15 : 886.31 = 455.95 : x
  2. Step 2: Convert to fraction form
    642.15/886.31 = 455.95/x
  3. Step 3: Cross multiply
    642.15x = 886.31 × 455.95
  4. Step 4: Simplify right side
    642.15x = 404,113.04
  5. Step 5: Solve for x
    x = 404,113.04/642.15
  6. Step 6: Final answer
    x = 629.31

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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.