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Finding the Fourth Proportional to 681.21, 939.80 and 419.38

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Solution

The fourth proportional to 681.21, 939.80 and 419.38 is: 578.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.21 : 939.80 = 419.38 : x
  2. Step 2: Convert to fraction form
    681.21/939.80 = 419.38/x
  3. Step 3: Cross multiply
    681.21x = 939.80 × 419.38
  4. Step 4: Simplify right side
    681.21x = 394,132.02
  5. Step 5: Solve for x
    x = 394,132.02/681.21
  6. Step 6: Final answer
    x = 578.58

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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.