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Finding the Fourth Proportional to 518.08, 777.60 and 390.08

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Solution

The fourth proportional to 518.08, 777.60 and 390.08 is: 585.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    518.08 : 777.60 = 390.08 : x
  2. Step 2: Convert to fraction form
    518.08/777.60 = 390.08/x
  3. Step 3: Cross multiply
    518.08x = 777.60 × 390.08
  4. Step 4: Simplify right side
    518.08x = 303,326.21
  5. Step 5: Solve for x
    x = 303,326.21/518.08
  6. Step 6: Final answer
    x = 585.48

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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.