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Finding the Fourth Proportional to 1,080, 1,620.40 and 647.46

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Solution

The fourth proportional to 1,080, 1,620.40 and 647.46 is: 971.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,080 : 1,620.40 = 647.46 : x
  2. Step 2: Convert to fraction form
    1,080/1,620.40 = 647.46/x
  3. Step 3: Cross multiply
    1,080x = 1,620.40 × 647.46
  4. Step 4: Simplify right side
    1,080x = 1,049,144.18
  5. Step 5: Solve for x
    x = 1,049,144.18/1,080
  6. Step 6: Final answer
    x = 971.43

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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.