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Finding the Fourth Proportional to 505.80, 696.60 and 389.16

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Solution

The fourth proportional to 505.80, 696.60 and 389.16 is: 535.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    505.80 : 696.60 = 389.16 : x
  2. Step 2: Convert to fraction form
    505.80/696.60 = 389.16/x
  3. Step 3: Cross multiply
    505.80x = 696.60 × 389.16
  4. Step 4: Simplify right side
    505.80x = 271,088.86
  5. Step 5: Solve for x
    x = 271,088.86/505.80
  6. Step 6: Final answer
    x = 535.96

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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.