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Finding the Fourth Proportional to 665.00, 917.72 and 399.60

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Solution

The fourth proportional to 665.00, 917.72 and 399.60 is: 551.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.00 : 917.72 = 399.60 : x
  2. Step 2: Convert to fraction form
    665.00/917.72 = 399.60/x
  3. Step 3: Cross multiply
    665.00x = 917.72 × 399.60
  4. Step 4: Simplify right side
    665.00x = 366,720.41
  5. Step 5: Solve for x
    x = 366,720.41/665.00
  6. Step 6: Final answer
    x = 551.46

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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.