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Finding the Fourth Proportional to 681.28, 939.91 and 415.63

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Solution

The fourth proportional to 681.28, 939.91 and 415.63 is: 573.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.28 : 939.91 = 415.63 : x
  2. Step 2: Convert to fraction form
    681.28/939.91 = 415.63/x
  3. Step 3: Cross multiply
    681.28x = 939.91 × 415.63
  4. Step 4: Simplify right side
    681.28x = 390,649.25
  5. Step 5: Solve for x
    x = 390,649.25/681.28
  6. Step 6: Final answer
    x = 573.41

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1.5x scale

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.