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Finding the Fourth Proportional to 681.40, 939.30 and 663.16

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Solution

The fourth proportional to 681.40, 939.30 and 663.16 is: 914.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.40 : 939.30 = 663.16 : x
  2. Step 2: Convert to fraction form
    681.40/939.30 = 663.16/x
  3. Step 3: Cross multiply
    681.40x = 939.30 × 663.16
  4. Step 4: Simplify right side
    681.40x = 622,906.19
  5. Step 5: Solve for x
    x = 622,906.19/681.40
  6. Step 6: Final answer
    x = 914.16

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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.