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Finding the Fourth Proportional to 56.42, 77.85 and 40.05

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Solution

The fourth proportional to 56.42, 77.85 and 40.05 is: 55.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    56.42 : 77.85 = 40.05 : x
  2. Step 2: Convert to fraction form
    56.42/77.85 = 40.05/x
  3. Step 3: Cross multiply
    56.42x = 77.85 × 40.05
  4. Step 4: Simplify right side
    56.42x = 3,117.50
  5. Step 5: Solve for x
    x = 3,117.50/56.42
  6. Step 6: Final answer
    x = 55.26

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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.