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Finding the Fourth Proportional to 79.90, 110.20 and 56.55

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Solution

The fourth proportional to 79.90, 110.20 and 56.55 is: 78.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.90 : 110.20 = 56.55 : x
  2. Step 2: Convert to fraction form
    79.90/110.20 = 56.55/x
  3. Step 3: Cross multiply
    79.90x = 110.20 × 56.55
  4. Step 4: Simplify right side
    79.90x = 6,231.81
  5. Step 5: Solve for x
    x = 6,231.81/79.90
  6. Step 6: Final answer
    x = 78.00

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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.