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Finding the Fourth Proportional to 421.77, 581.65 and 305.13

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Solution

The fourth proportional to 421.77, 581.65 and 305.13 is: 420.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.77 : 581.65 = 305.13 : x
  2. Step 2: Convert to fraction form
    421.77/581.65 = 305.13/x
  3. Step 3: Cross multiply
    421.77x = 581.65 × 305.13
  4. Step 4: Simplify right side
    421.77x = 177,478.86
  5. Step 5: Solve for x
    x = 177,478.86/421.77
  6. Step 6: Final answer
    x = 420.80

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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.