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Finding the Fourth Proportional to 93.51, 128.63 and 76.80

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Solution

The fourth proportional to 93.51, 128.63 and 76.80 is: 105.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    93.51 : 128.63 = 76.80 : x
  2. Step 2: Convert to fraction form
    93.51/128.63 = 76.80/x
  3. Step 3: Cross multiply
    93.51x = 128.63 × 76.80
  4. Step 4: Simplify right side
    93.51x = 9,878.40
  5. Step 5: Solve for x
    x = 9,878.40/93.51
  6. Step 6: Final answer
    x = 105.64

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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.