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Finding the Fourth Proportional to 661.91, 992.66 and 430.79

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Solution

The fourth proportional to 661.91, 992.66 and 430.79 is: 646.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.91 : 992.66 = 430.79 : x
  2. Step 2: Convert to fraction form
    661.91/992.66 = 430.79/x
  3. Step 3: Cross multiply
    661.91x = 992.66 × 430.79
  4. Step 4: Simplify right side
    661.91x = 427,620.88
  5. Step 5: Solve for x
    x = 427,620.88/661.91
  6. Step 6: Final answer
    x = 646.05

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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.