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Finding the Fourth Proportional to 58.80, 81.60 and 56.40

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Solution

The fourth proportional to 58.80, 81.60 and 56.40 is: 78.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    58.80 : 81.60 = 56.40 : x
  2. Step 2: Convert to fraction form
    58.80/81.60 = 56.40/x
  3. Step 3: Cross multiply
    58.80x = 81.60 × 56.40
  4. Step 4: Simplify right side
    58.80x = 4,602.24
  5. Step 5: Solve for x
    x = 4,602.24/58.80
  6. Step 6: Final answer
    x = 78.27

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.