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Finding the Fourth Proportional to 699.80, 965.81 and 420.18

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Solution

The fourth proportional to 699.80, 965.81 and 420.18 is: 579.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    699.80 : 965.81 = 420.18 : x
  2. Step 2: Convert to fraction form
    699.80/965.81 = 420.18/x
  3. Step 3: Cross multiply
    699.80x = 965.81 × 420.18
  4. Step 4: Simplify right side
    699.80x = 405,811.94
  5. Step 5: Solve for x
    x = 405,811.94/699.80
  6. Step 6: Final answer
    x = 579.90

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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.