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Finding the Fourth Proportional to 680.38, 1,015.01 and 661.55

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Solution

The fourth proportional to 680.38, 1,015.01 and 661.55 is: 986.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.38 : 1,015.01 = 661.55 : x
  2. Step 2: Convert to fraction form
    680.38/1,015.01 = 661.55/x
  3. Step 3: Cross multiply
    680.38x = 1,015.01 × 661.55
  4. Step 4: Simplify right side
    680.38x = 671,476.44
  5. Step 5: Solve for x
    x = 671,476.44/680.38
  6. Step 6: Final answer
    x = 986.92

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.