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Finding the Fourth Proportional to 430.70, 645.72 and 214.43

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Solution

The fourth proportional to 430.70, 645.72 and 214.43 is: 321.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.70 : 645.72 = 214.43 : x
  2. Step 2: Convert to fraction form
    430.70/645.72 = 214.43/x
  3. Step 3: Cross multiply
    430.70x = 645.72 × 214.43
  4. Step 4: Simplify right side
    430.70x = 138,458.51
  5. Step 5: Solve for x
    x = 138,458.51/430.70
  6. Step 6: Final answer
    x = 321.48

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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.