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Finding the Fourth Proportional to 681.10, 939.90 and 386.38

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Solution

The fourth proportional to 681.10, 939.90 and 386.38 is: 533.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.10 : 939.90 = 386.38 : x
  2. Step 2: Convert to fraction form
    681.10/939.90 = 386.38/x
  3. Step 3: Cross multiply
    681.10x = 939.90 × 386.38
  4. Step 4: Simplify right side
    681.10x = 363,158.56
  5. Step 5: Solve for x
    x = 363,158.56/681.10
  6. Step 6: Final answer
    x = 533.19

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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.