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Finding the Fourth Proportional to 982.61, 1,355.12 and 646.21

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Solution

The fourth proportional to 982.61, 1,355.12 and 646.21 is: 891.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    982.61 : 1,355.12 = 646.21 : x
  2. Step 2: Convert to fraction form
    982.61/1,355.12 = 646.21/x
  3. Step 3: Cross multiply
    982.61x = 1,355.12 × 646.21
  4. Step 4: Simplify right side
    982.61x = 875,692.10
  5. Step 5: Solve for x
    x = 875,692.10/982.61
  6. Step 6: Final answer
    x = 891.19

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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.