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Finding the Fourth Proportional to 991.55, 1,487.49 and 443.72

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Solution

The fourth proportional to 991.55, 1,487.49 and 443.72 is: 665.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    991.55 : 1,487.49 = 443.72 : x
  2. Step 2: Convert to fraction form
    991.55/1,487.49 = 443.72/x
  3. Step 3: Cross multiply
    991.55x = 1,487.49 × 443.72
  4. Step 4: Simplify right side
    991.55x = 660,029.06
  5. Step 5: Solve for x
    x = 660,029.06/991.55
  6. Step 6: Final answer
    x = 665.65

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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.