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Finding the Fourth Proportional to 689.67, 1,035.02 and 430.05

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Solution

The fourth proportional to 689.67, 1,035.02 and 430.05 is: 645.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.67 : 1,035.02 = 430.05 : x
  2. Step 2: Convert to fraction form
    689.67/1,035.02 = 430.05/x
  3. Step 3: Cross multiply
    689.67x = 1,035.02 × 430.05
  4. Step 4: Simplify right side
    689.67x = 445,110.35
  5. Step 5: Solve for x
    x = 445,110.35/689.67
  6. Step 6: Final answer
    x = 645.40

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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.