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Finding the Fourth Proportional to 78.99, 117.70 and 75.50

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Solution

The fourth proportional to 78.99, 117.70 and 75.50 is: 112.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.99 : 117.70 = 75.50 : x
  2. Step 2: Convert to fraction form
    78.99/117.70 = 75.50/x
  3. Step 3: Cross multiply
    78.99x = 117.70 × 75.50
  4. Step 4: Simplify right side
    78.99x = 8,885.38
  5. Step 5: Solve for x
    x = 8,885.38/78.99
  6. Step 6: Final answer
    x = 112.49

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.