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Finding the Fourth Proportional to 386.65, 580.07 and 278.65

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Solution

The fourth proportional to 386.65, 580.07 and 278.65 is: 418.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.65 : 580.07 = 278.65 : x
  2. Step 2: Convert to fraction form
    386.65/580.07 = 278.65/x
  3. Step 3: Cross multiply
    386.65x = 580.07 × 278.65
  4. Step 4: Simplify right side
    386.65x = 161,636.51
  5. Step 5: Solve for x
    x = 161,636.51/386.65
  6. Step 6: Final answer
    x = 418.04

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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.