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Finding the Fourth Proportional to 665.64, 995.90 and 405.60

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Solution

The fourth proportional to 665.64, 995.90 and 405.60 is: 606.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.64 : 995.90 = 405.60 : x
  2. Step 2: Convert to fraction form
    665.64/995.90 = 405.60/x
  3. Step 3: Cross multiply
    665.64x = 995.90 × 405.60
  4. Step 4: Simplify right side
    665.64x = 403,937.04
  5. Step 5: Solve for x
    x = 403,937.04/665.64
  6. Step 6: Final answer
    x = 606.84

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.