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Finding the Fourth Proportional to 72.50, 108.75 and 71.60

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Solution

The fourth proportional to 72.50, 108.75 and 71.60 is: 107.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.50 : 108.75 = 71.60 : x
  2. Step 2: Convert to fraction form
    72.50/108.75 = 71.60/x
  3. Step 3: Cross multiply
    72.50x = 108.75 × 71.60
  4. Step 4: Simplify right side
    72.50x = 7,786.50
  5. Step 5: Solve for x
    x = 7,786.50/72.50
  6. Step 6: Final answer
    x = 107.40

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.