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Finding the Fourth Proportional to 1,317.90, 1,818.81 and 728.49

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Solution

The fourth proportional to 1,317.90, 1,818.81 and 728.49 is: 1,005.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,317.90 : 1,818.81 = 728.49 : x
  2. Step 2: Convert to fraction form
    1,317.90/1,818.81 = 728.49/x
  3. Step 3: Cross multiply
    1,317.90x = 1,818.81 × 728.49
  4. Step 4: Simplify right side
    1,317.90x = 1,324,984.90
  5. Step 5: Solve for x
    x = 1,324,984.90/1,317.90
  6. Step 6: Final answer
    x = 1,005.38

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1.5x scale

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.