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Finding the Fourth Proportional to 681.36, 939.72 and 419.28

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Solution

The fourth proportional to 681.36, 939.72 and 419.28 is: 578.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.36 : 939.72 = 419.28 : x
  2. Step 2: Convert to fraction form
    681.36/939.72 = 419.28/x
  3. Step 3: Cross multiply
    681.36x = 939.72 × 419.28
  4. Step 4: Simplify right side
    681.36x = 394,005.80
  5. Step 5: Solve for x
    x = 394,005.80/681.36
  6. Step 6: Final answer
    x = 578.26

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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.