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Finding the Fourth Proportional to 665.80, 919.05 and 403.75

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Solution

The fourth proportional to 665.80, 919.05 and 403.75 is: 557.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.80 : 919.05 = 403.75 : x
  2. Step 2: Convert to fraction form
    665.80/919.05 = 403.75/x
  3. Step 3: Cross multiply
    665.80x = 919.05 × 403.75
  4. Step 4: Simplify right side
    665.80x = 371,066.44
  5. Step 5: Solve for x
    x = 371,066.44/665.80
  6. Step 6: Final answer
    x = 557.32

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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.