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Finding the Fourth Proportional to 1,009, 1,393.28 and 636.60

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Solution

The fourth proportional to 1,009, 1,393.28 and 636.60 is: 879.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,009 : 1,393.28 = 636.60 : x
  2. Step 2: Convert to fraction form
    1,009/1,393.28 = 636.60/x
  3. Step 3: Cross multiply
    1,009x = 1,393.28 × 636.60
  4. Step 4: Simplify right side
    1,009x = 886,962.05
  5. Step 5: Solve for x
    x = 886,962.05/1,009
  6. Step 6: Final answer
    x = 879.05

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.