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Finding the Fourth Proportional to 479.89, 661.80 and 305.20

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Solution

The fourth proportional to 479.89, 661.80 and 305.20 is: 420.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    479.89 : 661.80 = 305.20 : x
  2. Step 2: Convert to fraction form
    479.89/661.80 = 305.20/x
  3. Step 3: Cross multiply
    479.89x = 661.80 × 305.20
  4. Step 4: Simplify right side
    479.89x = 201,981.36
  5. Step 5: Solve for x
    x = 201,981.36/479.89
  6. Step 6: Final answer
    x = 420.89

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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.