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Finding the Fourth Proportional to 386.36, 578.74 and 215

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Solution

The fourth proportional to 386.36, 578.74 and 215 is: 322.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.36 : 578.74 = 215 : x
  2. Step 2: Convert to fraction form
    386.36/578.74 = 215/x
  3. Step 3: Cross multiply
    386.36x = 578.74 × 215
  4. Step 4: Simplify right side
    386.36x = 124,429.10
  5. Step 5: Solve for x
    x = 124,429.10/386.36
  6. Step 6: Final answer
    x = 322.05

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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.