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Finding the Fourth Proportional to 670.25, 1,010.31 and 642.47

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Solution

The fourth proportional to 670.25, 1,010.31 and 642.47 is: 968.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    670.25 : 1,010.31 = 642.47 : x
  2. Step 2: Convert to fraction form
    670.25/1,010.31 = 642.47/x
  3. Step 3: Cross multiply
    670.25x = 1,010.31 × 642.47
  4. Step 4: Simplify right side
    670.25x = 649,086.40
  5. Step 5: Solve for x
    x = 649,086.40/670.25
  6. Step 6: Final answer
    x = 968.42

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.