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Finding the Fourth Proportional to 505.80, 697.90 and 319.20

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Solution

The fourth proportional to 505.80, 697.90 and 319.20 is: 440.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    505.80 : 697.90 = 319.20 : x
  2. Step 2: Convert to fraction form
    505.80/697.90 = 319.20/x
  3. Step 3: Cross multiply
    505.80x = 697.90 × 319.20
  4. Step 4: Simplify right side
    505.80x = 222,769.68
  5. Step 5: Solve for x
    x = 222,769.68/505.80
  6. Step 6: Final answer
    x = 440.43

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1.5x scale

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.