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Finding the Fourth Proportional to 661.36, 991.56 and 405.04

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Solution

The fourth proportional to 661.36, 991.56 and 405.04 is: 607.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.36 : 991.56 = 405.04 : x
  2. Step 2: Convert to fraction form
    661.36/991.56 = 405.04/x
  3. Step 3: Cross multiply
    661.36x = 991.56 × 405.04
  4. Step 4: Simplify right side
    661.36x = 401,621.46
  5. Step 5: Solve for x
    x = 401,621.46/661.36
  6. Step 6: Final answer
    x = 607.27

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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.