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Finding the Fourth Proportional to 642.04, 886.40 and 421.38

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Solution

The fourth proportional to 642.04, 886.40 and 421.38 is: 581.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.04 : 886.40 = 421.38 : x
  2. Step 2: Convert to fraction form
    642.04/886.40 = 421.38/x
  3. Step 3: Cross multiply
    642.04x = 886.40 × 421.38
  4. Step 4: Simplify right side
    642.04x = 373,511.23
  5. Step 5: Solve for x
    x = 373,511.23/642.04
  6. Step 6: Final answer
    x = 581.75

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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.