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Finding the Fourth Proportional to 991.46, 1,487.42 and 342.20

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Solution

The fourth proportional to 991.46, 1,487.42 and 342.20 is: 513.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    991.46 : 1,487.42 = 342.20 : x
  2. Step 2: Convert to fraction form
    991.46/1,487.42 = 342.20/x
  3. Step 3: Cross multiply
    991.46x = 1,487.42 × 342.20
  4. Step 4: Simplify right side
    991.46x = 508,985.98
  5. Step 5: Solve for x
    x = 508,985.98/991.46
  6. Step 6: Final answer
    x = 513.37

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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.