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Finding the Fourth Proportional to 728.80, 1,003.74 and 664

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Solution

The fourth proportional to 728.80, 1,003.74 and 664 is: 914.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.80 : 1,003.74 = 664 : x
  2. Step 2: Convert to fraction form
    728.80/1,003.74 = 664/x
  3. Step 3: Cross multiply
    728.80x = 1,003.74 × 664
  4. Step 4: Simplify right side
    728.80x = 666,483.36
  5. Step 5: Solve for x
    x = 666,483.36/728.80
  6. Step 6: Final answer
    x = 914.49

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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.