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Finding the Fourth Proportional to 78.51, 108.36 and 53.66

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Solution

The fourth proportional to 78.51, 108.36 and 53.66 is: 74.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.51 : 108.36 = 53.66 : x
  2. Step 2: Convert to fraction form
    78.51/108.36 = 53.66/x
  3. Step 3: Cross multiply
    78.51x = 108.36 × 53.66
  4. Step 4: Simplify right side
    78.51x = 5,814.60
  5. Step 5: Solve for x
    x = 5,814.60/78.51
  6. Step 6: Final answer
    x = 74.06

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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.