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Finding the Fourth Proportional to 661.03, 990.83 and 430.09

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Solution

The fourth proportional to 661.03, 990.83 and 430.09 is: 644.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.03 : 990.83 = 430.09 : x
  2. Step 2: Convert to fraction form
    661.03/990.83 = 430.09/x
  3. Step 3: Cross multiply
    661.03x = 990.83 × 430.09
  4. Step 4: Simplify right side
    661.03x = 426,146.07
  5. Step 5: Solve for x
    x = 426,146.07/661.03
  6. Step 6: Final answer
    x = 644.67

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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.