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Finding the Fourth Proportional to 642.16, 886.20 and 455.60

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Solution

The fourth proportional to 642.16, 886.20 and 455.60 is: 628.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.16 : 886.20 = 455.60 : x
  2. Step 2: Convert to fraction form
    642.16/886.20 = 455.60/x
  3. Step 3: Cross multiply
    642.16x = 886.20 × 455.60
  4. Step 4: Simplify right side
    642.16x = 403,752.72
  5. Step 5: Solve for x
    x = 403,752.72/642.16
  6. Step 6: Final answer
    x = 628.74

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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.