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Finding the Fourth Proportional to 665.07, 917.71 and 399.45

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Solution

The fourth proportional to 665.07, 917.71 and 399.45 is: 551.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.07 : 917.71 = 399.45 : x
  2. Step 2: Convert to fraction form
    665.07/917.71 = 399.45/x
  3. Step 3: Cross multiply
    665.07x = 917.71 × 399.45
  4. Step 4: Simplify right side
    665.07x = 366,579.26
  5. Step 5: Solve for x
    x = 366,579.26/665.07
  6. Step 6: Final answer
    x = 551.19

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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.