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Finding the Fourth Proportional to 661.03, 912.21 and 428.16

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Solution

The fourth proportional to 661.03, 912.21 and 428.16 is: 590.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.03 : 912.21 = 428.16 : x
  2. Step 2: Convert to fraction form
    661.03/912.21 = 428.16/x
  3. Step 3: Cross multiply
    661.03x = 912.21 × 428.16
  4. Step 4: Simplify right side
    661.03x = 390,571.83
  5. Step 5: Solve for x
    x = 390,571.83/661.03
  6. Step 6: Final answer
    x = 590.85

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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.