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Finding the Fourth Proportional to 665.25, 918.05 and 389.25

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Solution

The fourth proportional to 665.25, 918.05 and 389.25 is: 537.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.25 : 918.05 = 389.25 : x
  2. Step 2: Convert to fraction form
    665.25/918.05 = 389.25/x
  3. Step 3: Cross multiply
    665.25x = 918.05 × 389.25
  4. Step 4: Simplify right side
    665.25x = 357,349.02
  5. Step 5: Solve for x
    x = 357,349.02/665.25
  6. Step 6: Final answer
    x = 537.17

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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.