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Finding the Fourth Proportional to 78.57, 107.93 and 70.40

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Solution

The fourth proportional to 78.57, 107.93 and 70.40 is: 96.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.57 : 107.93 = 70.40 : x
  2. Step 2: Convert to fraction form
    78.57/107.93 = 70.40/x
  3. Step 3: Cross multiply
    78.57x = 107.93 × 70.40
  4. Step 4: Simplify right side
    78.57x = 7,598.72
  5. Step 5: Solve for x
    x = 7,598.72/78.57
  6. Step 6: Final answer
    x = 96.71

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.