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Finding the Fourth Proportional to 991.47, 1,485.56 and 644.37

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Solution

The fourth proportional to 991.47, 1,485.56 and 644.37 is: 965.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    991.47 : 1,485.56 = 644.37 : x
  2. Step 2: Convert to fraction form
    991.47/1,485.56 = 644.37/x
  3. Step 3: Cross multiply
    991.47x = 1,485.56 × 644.37
  4. Step 4: Simplify right side
    991.47x = 957,247.08
  5. Step 5: Solve for x
    x = 957,247.08/991.47
  6. Step 6: Final answer
    x = 965.48

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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.