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Finding the Fourth Proportional to 661.14, 912.84 and 428.67

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Solution

The fourth proportional to 661.14, 912.84 and 428.67 is: 591.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.14 : 912.84 = 428.67 : x
  2. Step 2: Convert to fraction form
    661.14/912.84 = 428.67/x
  3. Step 3: Cross multiply
    661.14x = 912.84 × 428.67
  4. Step 4: Simplify right side
    661.14x = 391,307.12
  5. Step 5: Solve for x
    x = 391,307.12/661.14
  6. Step 6: Final answer
    x = 591.87

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.