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Finding the Fourth Proportional to 538.28, 742.80 and 305.40

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Solution

The fourth proportional to 538.28, 742.80 and 305.40 is: 421.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    538.28 : 742.80 = 305.40 : x
  2. Step 2: Convert to fraction form
    538.28/742.80 = 305.40/x
  3. Step 3: Cross multiply
    538.28x = 742.80 × 305.40
  4. Step 4: Simplify right side
    538.28x = 226,851.12
  5. Step 5: Solve for x
    x = 226,851.12/538.28
  6. Step 6: Final answer
    x = 421.44

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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.