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Finding the Fourth Proportional to 421.77, 581.79 and 305.40

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Solution

The fourth proportional to 421.77, 581.79 and 305.40 is: 421.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.77 : 581.79 = 305.40 : x
  2. Step 2: Convert to fraction form
    421.77/581.79 = 305.40/x
  3. Step 3: Cross multiply
    421.77x = 581.79 × 305.40
  4. Step 4: Simplify right side
    421.77x = 177,678.67
  5. Step 5: Solve for x
    x = 177,678.67/421.77
  6. Step 6: Final answer
    x = 421.27

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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.