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Finding the Fourth Proportional to 1,681.21, 2,521.80 and 640.97

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Solution

The fourth proportional to 1,681.21, 2,521.80 and 640.97 is: 961.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,681.21 : 2,521.80 = 640.97 : x
  2. Step 2: Convert to fraction form
    1,681.21/2,521.80 = 640.97/x
  3. Step 3: Cross multiply
    1,681.21x = 2,521.80 × 640.97
  4. Step 4: Simplify right side
    1,681.21x = 1,616,398.15
  5. Step 5: Solve for x
    x = 1,616,398.15/1,681.21
  6. Step 6: Final answer
    x = 961.45

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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.