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Finding the Fourth Proportional to 681.65, 1,021.77 and 407.87

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Solution

The fourth proportional to 681.65, 1,021.77 and 407.87 is: 611.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.65 : 1,021.77 = 407.87 : x
  2. Step 2: Convert to fraction form
    681.65/1,021.77 = 407.87/x
  3. Step 3: Cross multiply
    681.65x = 1,021.77 × 407.87
  4. Step 4: Simplify right side
    681.65x = 416,744.22
  5. Step 5: Solve for x
    x = 416,744.22/681.65
  6. Step 6: Final answer
    x = 611.38

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.