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Finding the Fourth Proportional to 499.10, 689.38 and 420.67

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Solution

The fourth proportional to 499.10, 689.38 and 420.67 is: 581.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    499.10 : 689.38 = 420.67 : x
  2. Step 2: Convert to fraction form
    499.10/689.38 = 420.67/x
  3. Step 3: Cross multiply
    499.10x = 689.38 × 420.67
  4. Step 4: Simplify right side
    499.10x = 290,003.21
  5. Step 5: Solve for x
    x = 290,003.21/499.10
  6. Step 6: Final answer
    x = 581.06

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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.