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Finding the Fourth Proportional to 661.43, 991.43 and 290.91

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Solution

The fourth proportional to 661.43, 991.43 and 290.91 is: 436.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.43 : 991.43 = 290.91 : x
  2. Step 2: Convert to fraction form
    661.43/991.43 = 290.91/x
  3. Step 3: Cross multiply
    661.43x = 991.43 × 290.91
  4. Step 4: Simplify right side
    661.43x = 288,421.35
  5. Step 5: Solve for x
    x = 288,421.35/661.43
  6. Step 6: Final answer
    x = 436.06

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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.