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Finding the Fourth Proportional to 78.96, 109.08 and 56.08

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Solution

The fourth proportional to 78.96, 109.08 and 56.08 is: 77.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.96 : 109.08 = 56.08 : x
  2. Step 2: Convert to fraction form
    78.96/109.08 = 56.08/x
  3. Step 3: Cross multiply
    78.96x = 109.08 × 56.08
  4. Step 4: Simplify right side
    78.96x = 6,117.21
  5. Step 5: Solve for x
    x = 6,117.21/78.96
  6. Step 6: Final answer
    x = 77.47

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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.