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Finding the Fourth Proportional to 660.05, 988.93 and 428.67

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Solution

The fourth proportional to 660.05, 988.93 and 428.67 is: 642.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.05 : 988.93 = 428.67 : x
  2. Step 2: Convert to fraction form
    660.05/988.93 = 428.67/x
  3. Step 3: Cross multiply
    660.05x = 988.93 × 428.67
  4. Step 4: Simplify right side
    660.05x = 423,924.62
  5. Step 5: Solve for x
    x = 423,924.62/660.05
  6. Step 6: Final answer
    x = 642.26

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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.