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Finding the Fourth Proportional to 78.07, 107.43 and 72.28

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Solution

The fourth proportional to 78.07, 107.43 and 72.28 is: 99.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.07 : 107.43 = 72.28 : x
  2. Step 2: Convert to fraction form
    78.07/107.43 = 72.28/x
  3. Step 3: Cross multiply
    78.07x = 107.43 × 72.28
  4. Step 4: Simplify right side
    78.07x = 7,765.04
  5. Step 5: Solve for x
    x = 7,765.04/78.07
  6. Step 6: Final answer
    x = 99.46

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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.