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Finding the Fourth Proportional to 986.20, 1,385 and 986.20

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Solution

The fourth proportional to 986.20, 1,385 and 986.20 is: 1,385

Step by Step Solution

  1. Step 1: Write the proportion equation
    986.20 : 1,385 = 986.20 : x
  2. Step 2: Convert to fraction form
    986.20/1,385 = 986.20/x
  3. Step 3: Cross multiply
    986.20x = 1,385 × 986.20
  4. Step 4: Simplify right side
    986.20x = 1,365,887
  5. Step 5: Solve for x
    x = 1,365,887/986.20
  6. Step 6: Final answer
    x = 1,385

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Why These Related Problems?

These problems maintain the same ratio (1.40) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.