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Finding the Fourth Proportional to 665.85, 918.87 and 386.25

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Solution

The fourth proportional to 665.85, 918.87 and 386.25 is: 533.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.85 : 918.87 = 386.25 : x
  2. Step 2: Convert to fraction form
    665.85/918.87 = 386.25/x
  3. Step 3: Cross multiply
    665.85x = 918.87 × 386.25
  4. Step 4: Simplify right side
    665.85x = 354,913.84
  5. Step 5: Solve for x
    x = 354,913.84/665.85
  6. Step 6: Final answer
    x = 533.03

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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.