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Finding the Fourth Proportional to 665.89, 918.80 and 386.14

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Solution

The fourth proportional to 665.89, 918.80 and 386.14 is: 532.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.89 : 918.80 = 386.14 : x
  2. Step 2: Convert to fraction form
    665.89/918.80 = 386.14/x
  3. Step 3: Cross multiply
    665.89x = 918.80 × 386.14
  4. Step 4: Simplify right side
    665.89x = 354,785.43
  5. Step 5: Solve for x
    x = 354,785.43/665.89
  6. Step 6: Final answer
    x = 532.80

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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.