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Finding the Fourth Proportional to 312.03, 430.65 and 305.19

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Solution

The fourth proportional to 312.03, 430.65 and 305.19 is: 421.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.03 : 430.65 = 305.19 : x
  2. Step 2: Convert to fraction form
    312.03/430.65 = 305.19/x
  3. Step 3: Cross multiply
    312.03x = 430.65 × 305.19
  4. Step 4: Simplify right side
    312.03x = 131,430.07
  5. Step 5: Solve for x
    x = 131,430.07/312.03
  6. Step 6: Final answer
    x = 421.21

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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.