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Finding the Fourth Proportional to 681.27, 939.75 and 428.79

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Solution

The fourth proportional to 681.27, 939.75 and 428.79 is: 591.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.27 : 939.75 = 428.79 : x
  2. Step 2: Convert to fraction form
    681.27/939.75 = 428.79/x
  3. Step 3: Cross multiply
    681.27x = 939.75 × 428.79
  4. Step 4: Simplify right side
    681.27x = 402,955.40
  5. Step 5: Solve for x
    x = 402,955.40/681.27
  6. Step 6: Final answer
    x = 591.48

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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.