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Finding the Fourth Proportional to 55.65, 76.78 and 40.08

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Solution

The fourth proportional to 55.65, 76.78 and 40.08 is: 55.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    55.65 : 76.78 = 40.08 : x
  2. Step 2: Convert to fraction form
    55.65/76.78 = 40.08/x
  3. Step 3: Cross multiply
    55.65x = 76.78 × 40.08
  4. Step 4: Simplify right side
    55.65x = 3,077.34
  5. Step 5: Solve for x
    x = 3,077.34/55.65
  6. Step 6: Final answer
    x = 55.30

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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.